Index: C:/dev/jackrabbit/src/test/java/org/apache/jackrabbit/test/api/ReferencesTest.java
===================================================================
--- C:/dev/jackrabbit/src/test/java/org/apache/jackrabbit/test/api/ReferencesTest.java	(revision 481177)
+++ C:/dev/jackrabbit/src/test/java/org/apache/jackrabbit/test/api/ReferencesTest.java	(working copy)
@@ -163,4 +163,34 @@
 	    fail("too many referers: " + iter.nextProperty().getPath());
 	}
     }
+
+    /**
+     * Tests getNodeReferences before saving
+     */
+    public void testGetReferences() throws RepositoryException {
+        Node n1 = testRootNode.addNode(nodeName1, testNodeType);
+        n1.addMixin(mixReferenceable);
+        Node n2 = testRootNode.addNode(nodeName2, testNodeType);
+        n2.addMixin(mixReferenceable);
+        // with some impls. the mixin type has only affect upon save
+        testRootNode.save();
+        // create references: n3.p1 -> n1
+        Node n3 = testRootNode.addNode(nodeName3, testNodeType);
+        n3.getSession().save();
+        n3.setProperty(propertyName1, n1);
+        n3.save();
+        PropertyIterator it = n1.getReferences();
+        boolean found = false;
+        while (it.hasNext()) {
+            Property p = it.nextProperty();
+            if (p.getName().equals(propertyName1)) {
+                found = true;
+            }
+        }
+        assertTrue("Unsaved property found in getReferences", found);
+        it = n2.getReferences();
+        assertFalse(it.hasNext());
+        n3.getSession().save();
+    }
+
 }
Index: C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/persistence/AbstractPersistenceManager.java
===================================================================
--- C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/persistence/AbstractPersistenceManager.java	(revision 481177)
+++ C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/persistence/AbstractPersistenceManager.java	(working copy)
@@ -21,7 +21,10 @@
 import org.apache.jackrabbit.core.state.ChangeLog;
 import org.apache.jackrabbit.core.state.ItemState;
 import org.apache.jackrabbit.core.state.ItemStateException;
+import org.apache.jackrabbit.core.state.NoSuchItemStateException;
 import org.apache.jackrabbit.core.state.NodeReferences;
+import org.apache.jackrabbit.core.state.NodeReferencesChanges;
+import org.apache.jackrabbit.core.state.NodeReferencesId;
 import org.apache.jackrabbit.core.state.NodeState;
 import org.apache.jackrabbit.core.state.PropertyState;
 
@@ -86,7 +89,22 @@
         }
         iter = changeLog.modifiedRefs();
         while (iter.hasNext()) {
-            NodeReferences refs = (NodeReferences) iter.next();
+            NodeReferencesChanges changes = (NodeReferencesChanges) iter.next();
+            NodeReferencesId id = changes.getId();
+            // load the list of references
+            // TODO the persistence manager should be able to merge changes itself
+            NodeReferences refs;
+            try {
+                refs = load(id);
+            } catch (NoSuchItemStateException e) {
+                // actually, it would be better if there is a method 'loadIfExists'
+                // that returns null if it does not exist
+                // calling a has... method first would maybe be another network
+                // roundtrip
+                refs = new NodeReferences(id);
+            }
+            // merge the changes
+            refs = refs.merge(changes);
             if (refs.hasReferences()) {
                 store(refs);
             } else {
Index: C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/virtual/VirtualItemStateProvider.java
===================================================================
--- C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/virtual/VirtualItemStateProvider.java	(revision 481177)
+++ C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/virtual/VirtualItemStateProvider.java	(working copy)
@@ -18,9 +18,10 @@
 
 import org.apache.jackrabbit.core.ItemId;
 import org.apache.jackrabbit.core.NodeId;
+import org.apache.jackrabbit.core.PropertyId;
 import org.apache.jackrabbit.core.state.ItemStateManager;
-import org.apache.jackrabbit.core.state.NodeReferences;
 import org.apache.jackrabbit.core.state.ItemStateListener;
+import org.apache.jackrabbit.core.state.NodeReferencesId;
 import org.apache.jackrabbit.name.QName;
 
 import javax.jcr.RepositoryException;
@@ -75,14 +76,20 @@
         throws RepositoryException;
 
     /**
-     * Informs this provider that the node references to one of its states has
-     * changed.
+     * Informs this provider that a node references has been added.
      *
-     * @param refs
-     * @return <code>true</code> if the reference target is one of its items.
+     * @param refId
+     * @param sourceId
      */
-    boolean setNodeReferences(NodeReferences refs);
+    void addReference(NodeReferencesId refsId, PropertyId sourceId);
 
+    /**
+     * Informs this provider that a node references has been deleted.
+     *
+     * @param refId
+     * @param sourceId
+     */
+    void deleteReference(NodeReferencesId refId, PropertyId sourceId);
 
     /**
      * Add an <code>ItemStateListener</code>
Index: C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/LocalItemStateManager.java
===================================================================
--- C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/LocalItemStateManager.java	(revision 481177)
+++ C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/LocalItemStateManager.java	(working copy)
@@ -185,20 +185,18 @@
      */
     public NodeReferences getNodeReferences(NodeReferencesId id)
             throws NoSuchItemStateException, ItemStateException {
-
-        // check change log
-        NodeReferences refs = changeLog.get(id);
-        if (refs != null) {
-            return refs;
+        NodeReferences references = sharedStateMgr.getNodeReferences(id);
+        NodeReferencesChanges changes = changeLog.get(id);
+        if (changes != null) {
+            references = references.merge(changes);
         }
-        return sharedStateMgr.getNodeReferences(id);
+        return references;
     }
 
     /**
      * {@inheritDoc}
      */
     public boolean hasNodeReferences(NodeReferencesId id) {
-        // check change log
         if (changeLog.get(id) != null) {
             return true;
         }
Index: C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/SharedItemStateManager.java
===================================================================
--- C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/SharedItemStateManager.java	(revision 481177)
+++ C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/SharedItemStateManager.java	(working copy)
@@ -18,6 +18,7 @@
 
 import EDU.oswego.cs.dl.util.concurrent.ReadWriteLock;
 import EDU.oswego.cs.dl.util.concurrent.ReentrantWriterPreferenceReadWriteLock;
+
 import org.apache.jackrabbit.core.ItemId;
 import org.apache.jackrabbit.core.NodeId;
 import org.apache.jackrabbit.core.PropertyId;
@@ -304,9 +305,16 @@
      */
     public NodeReferences getNodeReferences(NodeReferencesId id)
             throws NoSuchItemStateException, ItemStateException {
+        NodeReferences result = getNodeReferencesIfExists(id);
+        if (result == null) {
+            throw new NoSuchItemStateException(id.toString());
+        }
+        return result;
+    }
 
+    private NodeReferences getNodeReferencesIfExists(NodeReferencesId id)
+            throws NoSuchItemStateException, ItemStateException {
         acquireReadLock();
-
         try {
             // check persistence manager
             try {
@@ -322,12 +330,10 @@
                     // ignore
                 }
             }
+            return null;
         } finally {
             rwLock.readLock().release();
         }
-
-        // throw
-        throw new NoSuchItemStateException(id.toString());
     }
 
     /**
@@ -612,9 +618,9 @@
                 // filter out virtual node references for later processing
                 // (see comment above)
                 for (Iterator iter = local.modifiedRefs(); iter.hasNext();) {
-                    NodeReferences refs = (NodeReferences) iter.next();
+                    NodeReferencesChanges refChanges = (NodeReferencesChanges) iter.next();
                     boolean virtual = false;
-                    NodeId id = refs.getId().getTargetId();
+                    NodeId id = refChanges.getId().getTargetId();
                     for (int i = 0; i < virtualProviders.length; i++) {
                         if (virtualProviders[i].hasItemState(id)) {
                             List virtualRefs = virtualNodeReferences[i];
@@ -622,7 +628,7 @@
                                 virtualRefs = new LinkedList();
                                 virtualNodeReferences[i] = virtualRefs;
                             }
-                            virtualRefs.add(refs);
+                            virtualRefs.add(refChanges);
                             virtual = true;
                             break;
                         }
@@ -630,7 +636,14 @@
                     if (!virtual) {
                         // if target of node reference does not lie in a virtual
                         // space, add to modified set of normal provider.
-                        shared.modified(refs);
+                        for (Iterator it = refChanges.getAdded(); it.hasNext();) {
+                            PropertyId propId = (PropertyId) it.next();
+                            shared.referenceAdded(refChanges.getId(), propId);
+                        }
+                        for (Iterator it = refChanges.getDeleted(); it.hasNext();) {
+                            PropertyId propId = (PropertyId) it.next();
+                            shared.referenceDeleted(refChanges.getId(), propId);
+                        }
                     }
                 }
 
@@ -695,8 +708,18 @@
                     List virtualRefs = virtualNodeReferences[i];
                     if (virtualRefs != null) {
                         for (Iterator iter = virtualRefs.iterator(); iter.hasNext();) {
-                            NodeReferences refs = (NodeReferences) iter.next();
-                            virtualProviders[i].setNodeReferences(refs);
+                            NodeReferencesChanges refChanges = (NodeReferencesChanges) iter.next();
+                            NodeReferencesId refId = refChanges.getId();
+                            Iterator it = refChanges.getAdded();
+                            while (it.hasNext()) {
+                                PropertyId prop = (PropertyId) it.next();
+                                virtualProviders[i].addReference(refId, prop);
+                            }
+                            it = refChanges.getDeleted();
+                            while (it.hasNext()) {
+                                PropertyId prop = (PropertyId) it.next();
+                                virtualProviders[i].deleteReference(refId, prop);
+                            }
                         }
                     }
                 }
@@ -1159,12 +1182,8 @@
                                 && virtualProvider.hasNodeReferences(refsId)) {
                             continue;
                         }
-                        NodeReferences refs =
-                                getOrCreateNodeReferences(refsId, changes);
-                        // add reference
-                        refs.addReference(prop.getPropertyId());
                         // update change log
-                        changes.modified(refs);
+                        changes.referenceAdded(refsId, prop.getPropertyId());
                     }
                 }
             }
@@ -1189,16 +1208,8 @@
                                 && virtualProvider.hasNodeReferences(refsId)) {
                             continue;
                         }
-                        // either get node references from change log or load from
-                        // persistence manager
-                        NodeReferences refs = changes.get(refsId);
-                        if (refs == null) {
-                            refs = getNodeReferences(refsId);
-                        }
-                        // remove reference
-                        refs.removeReference(oldProp.getPropertyId());
                         // update change log
-                        changes.modified(refs);
+                        changes.referenceDeleted(refsId, oldProp.getPropertyId());
                     }
                 }
                 // check new type
@@ -1213,12 +1224,8 @@
                                 && virtualProvider.hasNodeReferences(refsId)) {
                             continue;
                         }
-                        NodeReferences refs =
-                                getOrCreateNodeReferences(refsId, changes);
-                        // add reference
-                        refs.addReference(newProp.getPropertyId());
                         // update change log
-                        changes.modified(refs);
+                        changes.referenceAdded(refsId, newProp.getPropertyId());
                     }
                 }
             }
@@ -1240,16 +1247,8 @@
                                 && virtualProvider.hasNodeReferences(refsId)) {
                             continue;
                         }
-                        // either get node references from change log or
-                        // load from persistence manager
-                        NodeReferences refs = changes.get(refsId);
-                        if (refs == null) {
-                            refs = getNodeReferences(refsId);
-                        }
-                        // remove reference
-                        refs.removeReference(prop.getPropertyId());
                         // update change log
-                        changes.modified(refs);
+                        changes.referenceDeleted(refsId, prop.getPropertyId());
                     }
                 }
             }
@@ -1257,37 +1256,6 @@
     }
 
     /**
-     * Returns a node references object using the following rules:<p/>
-     * <ul>
-     * <li>1. return a modified instance from the change log (if one exists)</li>
-     * <li>2. return an existing instance from <i>this</i> item state manager
-     * (if one exists)</li>
-     * <li>3. create and return a new instance</li>
-     * </ul>
-     *
-     * @param refsId  node references id
-     * @param changes change log
-     * @return a node references object
-     * @throws ItemStateException if an error occurs
-     */
-    private NodeReferences getOrCreateNodeReferences(NodeReferencesId refsId,
-                                                     ChangeLog changes)
-            throws ItemStateException {
-        // check change log
-        NodeReferences refs = changes.get(refsId);
-        if (refs == null) {
-            // not yet in change log:
-            // either load existing or create new
-            if (hasNodeReferences(refsId)) {
-                refs = getNodeReferences(refsId);
-            } else {
-                refs = new NodeReferences(refsId);
-            }
-        }
-        return refs;
-    }
-
-    /**
      * Verifies that
      * <ul>
      * <li>no referenceable nodes are deleted if they are still being referenced</li>
@@ -1313,13 +1281,17 @@
                     NodeReferencesId refsId = new NodeReferencesId(node.getNodeId());
                     // either get node references from change log or
                     // load from persistence manager
-                    NodeReferences refs = changes.get(refsId);
-                    if (refs == null) {
+                    NodeReferencesChanges refChanges = changes.get(refsId);
+                    if (refChanges == null) {
                         if (!hasNodeReferences(refsId)) {
                             continue;
                         }
-                        refs = getNodeReferences(refsId);
                     }
+                    NodeReferences refs = getNodeReferencesIfExists(refsId);
+                    if (refs == null) {
+                        refs = new NodeReferences(refsId);
+                    }
+                    refs = refs.merge(refChanges);
                     // in some versioning operations (such as restore) a node
                     // may actually be deleted and then again added with the
                     // same UUID, i.e. the node is still referenceable.
@@ -1333,12 +1305,12 @@
             }
         }
 
-        // check whether targets of modified node references exist
+        // check whether targets of added node references exist
         for (Iterator iter = changes.modifiedRefs(); iter.hasNext();) {
-            NodeReferences refs = (NodeReferences) iter.next();
-            NodeId id = refs.getTargetId();
+            NodeReferencesChanges refChanges = (NodeReferencesChanges) iter.next();
+            NodeId id = refChanges.getId().getTargetId();
             // no need to check existence of target if there are no references
-            if (refs.hasReferences()) {
+            if (refChanges.getAddedSize() > 0) {
                 // please note:
                 // virtual providers are indirectly checked via 'hasItemState()'
                 if (!changes.has(id) && !hasItemState(id)) {
Index: C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/NodeReferencesChanges.java
===================================================================
--- C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/NodeReferencesChanges.java	(revision 0)
+++ C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/NodeReferencesChanges.java	(revision 0)
@@ -0,0 +1,97 @@
+package org.apache.jackrabbit.core.state;
+
+import org.apache.jackrabbit.core.PropertyId;
+
+import java.util.HashSet;
+import java.util.Iterator;
+
+/**
+ * <code>NodeReferencesChanges</code> represents changes (additions and removals) of references
+ * (i.e. properties of type <code>REFERENCE</code>) to a particular node (denoted by its uuid).
+ */
+public class NodeReferencesChanges {
+
+    /**
+     * The id of the target node.
+     */
+    private final NodeReferencesId targetNodeId;
+
+    /**
+     * The set of removed properties.
+     */
+    private HashSet deleted = new HashSet();
+
+    /**
+     * The set of added properties.
+     */
+    private HashSet added = new HashSet();
+
+    NodeReferencesChanges(NodeReferencesId targetNodeId) {
+        this.targetNodeId = targetNodeId;
+    }
+
+    /**
+     * Add a reference.
+     * If this property is in the 'delete' set, it is removed there;
+     * otherwise it is added to the 'add' set.
+     * @param sourcePropertyId
+     */
+    public void add(PropertyId sourcePropertyId) {
+        if (!deleted.remove(sourcePropertyId)) {
+            added.add(sourcePropertyId);
+        }
+    }
+
+    /**
+     * Remove a reference.
+     * If this property is in the 'add' set, it is removed there;
+     * otherwise it is added to the 'delete' set.
+     * @param sourcePropertyId
+     */
+    public void delete(PropertyId sourcePropertyId) {
+        if (!added.remove(sourcePropertyId)) {
+            deleted.add(sourcePropertyId);
+        }
+    }
+
+    /**
+     * Get the node references id
+     * @return the id
+     */
+    public NodeReferencesId getId() {
+        return targetNodeId;
+    }
+
+    /**
+     * Get an iterator for the 'add' set.
+     * @return the iterator
+     */
+    public Iterator getAdded() {
+        return added.iterator();
+    }
+
+    /**
+     * Get an iterator for the 'delete' set.
+     * @return the iterator
+     */
+    public Iterator getDeleted() {
+        return deleted.iterator();
+    }
+
+    /**
+     * Get the combined size of both the 'add' and the 'delete' set.
+     * @return the size
+     */
+    public int size() {
+        return deleted.size() + added.size();
+    }
+
+    /**
+     * Get the size of the 'add' set.
+     * @return the size
+     */
+    public int getAddedSize() {
+        return added.size();
+    }
+
+}
Index: C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/XAItemStateManager.java
===================================================================
--- C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/XAItemStateManager.java	(revision 481177)
+++ C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/XAItemStateManager.java	(working copy)
@@ -274,13 +274,12 @@
             return virtualProvider.getNodeReferences(id);
         }
         ChangeLog changeLog = getChangeLog();
+        NodeReferences refs = super.getNodeReferences(id);
         if (changeLog != null) {
-            NodeReferences refs = changeLog.get(id);
-            if (refs != null) {
-                return refs;
-            }
+            NodeReferencesChanges changes = changeLog.get(id);
+            refs = refs.merge(changes);
         }
-        return super.getNodeReferences(id);
+        return refs;
     }
 
     /**
@@ -395,14 +394,9 @@
                                      NodeReferencesId refsId)
             throws NoSuchItemStateException, ItemStateException {
 
-        NodeReferences refs = virtualProvider.getNodeReferences(refsId);
-        if (refs == null && virtualProvider.hasItemState(refsId.getTargetId())) {
-            refs = new NodeReferences(refsId);
+        if (!virtualProvider.hasNodeReferences(refsId) && virtualProvider.hasItemState(refsId.getTargetId())) {
+            virtualProvider.addReference(refsId, sourceId);
         }
-        if (refs != null) {
-            refs.addReference(sourceId);
-            virtualProvider.setNodeReferences(refs);
-        }
     }
 
     /**
@@ -416,13 +410,8 @@
                                         NodeReferencesId refsId)
             throws NoSuchItemStateException, ItemStateException {
 
-        NodeReferences refs = virtualProvider.getNodeReferences(refsId);
-        if (refs == null && virtualProvider.hasItemState(refsId.getTargetId())) {
-            refs = new NodeReferences(refsId);
+        if (!virtualProvider.hasNodeReferences(refsId) && virtualProvider.hasItemState(refsId.getTargetId())) {
+            virtualProvider.deleteReference(refsId, sourceId);
         }
-        if (refs != null) {
-            refs.removeReference(sourceId);
-            virtualProvider.setNodeReferences(refs);
-        }
     }
 }
Index: C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/ChangeLog.java
===================================================================
--- C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/ChangeLog.java	(revision 481177)
+++ C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/ChangeLog.java	(working copy)
@@ -18,6 +18,7 @@
 
 import org.apache.commons.collections.map.LinkedMap;
 import org.apache.jackrabbit.core.ItemId;
+import org.apache.jackrabbit.core.PropertyId;
 
 import java.util.Iterator;
 import java.util.Map;
@@ -90,15 +91,46 @@
     }
 
     /**
-     * A references has been modified
+     * A reference has been added.
      *
-     * @param refs refs that has been modified
+     * @param ref the reference that has been added
+     * @param sourcePropertyId the referencing property
      */
-    public void modified(NodeReferences refs) {
-        modifiedRefs.put(refs.getId(), refs);
+    public void referenceAdded(NodeReferencesId ref, PropertyId sourcePropertyId) {
+        NodeReferencesChanges changes = (NodeReferencesChanges) modifiedRefs.get(ref);
+        if (changes == null) {
+            changes = new NodeReferencesChanges(ref);
+            changes.add(sourcePropertyId);
+            modifiedRefs.put(ref, changes);
+        } else {
+            changes.add(sourcePropertyId);
+            if (changes.size() == 0) {
+                modifiedRefs.remove(ref);
+            }
+        }
     }
 
     /**
+     * A reference has been removed.
+     *
+     * @param ref the reference that has been removed
+     * @param sourcePropertyId the referencing property
+     */
+    public void referenceDeleted(NodeReferencesId ref, PropertyId sourcePropertyId) {
+        NodeReferencesChanges changes = (NodeReferencesChanges) modifiedRefs.get(ref);
+        if (changes == null) {
+            changes = new NodeReferencesChanges(ref);
+            changes.delete(sourcePropertyId);
+            modifiedRefs.put(ref, changes);
+        } else {
+            changes.delete(sourcePropertyId);
+            if (changes.size() == 0) {
+                modifiedRefs.remove(ref);
+            }
+        }
+    }
+
+    /**
      * Return an item state given its id. Returns <code>null</code>
      * if the item state is neither in the added nor in the modified
      * section. Throws a <code>NoSuchItemStateException</code> if
@@ -142,14 +174,14 @@
     }
 
     /**
-     * Return a node references object given its id. Returns
+     * Return a node references changes object given its id. Returns
      * <code>null</code> if the node reference is not in the modified
      * section.
      *
-     * @return node references or <code>null</code>
+     * @return node references changes or <code>null</code>
      */
-    public NodeReferences get(NodeReferencesId id) {
-        return (NodeReferences) modifiedRefs.get(id);
+    public NodeReferencesChanges get(NodeReferencesId id) {
+        return (NodeReferencesChanges) modifiedRefs.get(id);
     }
 
     /**
@@ -180,9 +212,9 @@
     }
 
     /**
-     * Return an iterator over all modified references.
+     * Return an iterator over all references changes.
      *
-     * @return iterator over all modified references.
+     * @return iterator over all references changes.
      */
     public Iterator modifiedRefs() {
         return modifiedRefs.values().iterator();
@@ -235,9 +267,22 @@
                 addedStates.put(state.getId(), state);
             }
         }
-
-        // add refs
-        modifiedRefs.putAll(other.modifiedRefs);
+        // changed references
+        iter = other.modifiedRefs.keySet().iterator();
+        while (iter.hasNext()) {
+            NodeReferencesId ref = (NodeReferencesId) iter.next();
+            NodeReferencesChanges changes = other.get(ref);
+            Iterator itAdded = changes.getAdded();
+            while (itAdded.hasNext()) {
+                PropertyId prop = (PropertyId) itAdded.next();
+                referenceAdded(ref, prop);
+            }
+            Iterator itDeleted = changes.getDeleted();
+            while (itDeleted.hasNext()) {
+                PropertyId prop = (PropertyId) itDeleted.next();
+                referenceDeleted(ref, prop);
+            }
+        }
     }
 
     /**
Index: C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/NodeReferences.java
===================================================================
--- C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/NodeReferences.java	(revision 481177)
+++ C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/state/NodeReferences.java	(working copy)
@@ -22,6 +22,7 @@
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.Iterator;
 import java.util.List;
 
 /**
@@ -123,4 +124,23 @@
     public void clearAllReferences() {
         references.clear();
     }
+
+    public NodeReferences merge(NodeReferencesChanges changes) {
+        if (changes == null || (changes.size() == 0)) {
+            return this;
+        }
+        NodeReferences copy = new NodeReferences(id);
+        copy.references = new ArrayList(references);
+        Iterator it = changes.getAdded();
+        while (it.hasNext()) {
+            PropertyId propId = (PropertyId) it.next();
+            copy.addReference(propId);
+        }
+        it = changes.getDeleted();
+        while (it.hasNext()) {
+            PropertyId propId = (PropertyId) it.next();
+            copy.removeReference(propId);
+        }
+        return copy;
+    }
 }
Index: C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/version/VersionManagerImpl.java
===================================================================
--- C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/version/VersionManagerImpl.java	(revision 481177)
+++ C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/version/VersionManagerImpl.java	(working copy)
@@ -36,6 +36,7 @@
 import org.apache.jackrabbit.core.state.ItemStateListener;
 import org.apache.jackrabbit.core.state.LocalItemStateManager;
 import org.apache.jackrabbit.core.state.NodeReferences;
+import org.apache.jackrabbit.core.state.NodeReferencesChanges;
 import org.apache.jackrabbit.core.state.NodeReferencesId;
 import org.apache.jackrabbit.core.state.NodeState;
 import org.apache.jackrabbit.core.state.PropertyState;
@@ -405,30 +406,39 @@
     }
 
     /**
-     * Sets and stored the node references from external nodes.
+     * Adds a reference to a node from external nodes.
      * @param references
-     * @return <code>true</code> if the references could be set.
      */
-    public boolean setNodeReferences(NodeReferences references) {
+    public void addReference(NodeReferencesId refsId, PropertyId sourceId) {
         acquireWriteLock();
         try {
             // filter out version storage intern ones
-            NodeReferences refs = new NodeReferences(references.getId());
-            Iterator iter = references.getReferences().iterator();
-            while (iter.hasNext()) {
-                PropertyId id = (PropertyId) iter.next();
-                if (!hasItem(id.getParentId())) {
-                    refs.addReference(id);
-                }
+            if (!hasItem(sourceId.getParentId())) {
+                ChangeLog log = new ChangeLog();
+                log.referenceAdded(refsId, sourceId);
+                pMgr.store(log);
             }
+        } catch (ItemStateException e) {
+            log.error("Error while setting references: " + e.toString());
+        } finally {
+            releaseWriteLock();
+        }
+    }
 
-            ChangeLog log = new ChangeLog();
-            log.modified(refs);
-            pMgr.store(log);
-            return true;
+    /**
+     * {@inheritDoc}
+     */
+    public void deleteReference(NodeReferencesId refsId, PropertyId sourceId) {
+        acquireWriteLock();
+        try {
+            // filter out version storage intern ones
+            if (!hasItem(sourceId.getParentId())) {
+                ChangeLog log = new ChangeLog();
+                log.referenceDeleted(refsId, sourceId);
+                pMgr.store(log);
+            }
         } catch (ItemStateException e) {
             log.error("Error while setting references: " + e.toString());
-            return false;
         } finally {
             releaseWriteLock();
         }
@@ -534,10 +544,11 @@
 
             // check whether targets of modified node references exist
             for (Iterator iter = changes.modifiedRefs(); iter.hasNext();) {
-                NodeReferences refs = (NodeReferences) iter.next();
-                NodeId id = refs.getTargetId();
-                // no need to check existence of target if there are no references
-                if (refs.hasReferences()) {
+                NodeReferencesChanges refChanges = (NodeReferencesChanges) iter.next();
+                NodeReferencesId refId = refChanges.getId();
+                NodeId id = refId.getTargetId();
+                // no need to check existence of target if there are no added or deleted references
+                if (refChanges.size() > 0) {
                     if (!changes.has(id) && !hasItemState(id)) {
                         // remove references
                         iter.remove();
Index: C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/version/XAVersionManager.java
===================================================================
--- C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/version/XAVersionManager.java	(revision 481177)
+++ C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/version/XAVersionManager.java	(working copy)
@@ -20,6 +20,7 @@
 import org.apache.jackrabbit.core.ItemId;
 import org.apache.jackrabbit.core.NodeId;
 import org.apache.jackrabbit.core.NodeImpl;
+import org.apache.jackrabbit.core.PropertyId;
 import org.apache.jackrabbit.core.SessionImpl;
 import org.apache.jackrabbit.core.TransactionContext;
 import org.apache.jackrabbit.core.TransactionException;
@@ -33,6 +34,7 @@
 import org.apache.jackrabbit.core.state.ItemStateListener;
 import org.apache.jackrabbit.core.state.NoSuchItemStateException;
 import org.apache.jackrabbit.core.state.NodeReferences;
+import org.apache.jackrabbit.core.state.NodeReferencesChanges;
 import org.apache.jackrabbit.core.state.NodeReferencesId;
 import org.apache.jackrabbit.core.state.NodeState;
 import org.apache.jackrabbit.core.state.XAItemStateManager;
@@ -243,17 +245,25 @@
     /**
      * {@inheritDoc}
      */
-    public boolean setNodeReferences(NodeReferences refs) {
+    public void addReference(NodeReferencesId refsId, PropertyId sourceId) {
         ChangeLog changeLog = ((XAItemStateManager) stateMgr).getChangeLog();
         if (changeLog != null) {
-            changeLog.modified(refs);
-            return true;
+            changeLog.referenceAdded(refsId, sourceId);
         }
-        return false;
     }
 
     /**
      * {@inheritDoc}
+     */
+    public void deleteReference(NodeReferencesId refId, PropertyId prop) {
+        ChangeLog changeLog = ((XAItemStateManager) stateMgr).getChangeLog();
+        if (changeLog != null) {
+            changeLog.referenceDeleted(refId, prop);
+        }
+    }
+
+    /**
+     * {@inheritDoc}
      * <p/>
      * Return item states for changes only. Global version manager will return
      * other items.
@@ -284,11 +294,16 @@
      */
     public NodeReferences getNodeReferences(NodeReferencesId id)
             throws NoSuchItemStateException, ItemStateException {
-
         ChangeLog changeLog = ((XAItemStateManager) stateMgr).getChangeLog();
-        if (changeLog != null) {
-            return changeLog.get(id);
+        NodeReferencesChanges changes = changeLog.get(id);
+        if (changes == null) {
+            return null;
         }
+        NodeReferences refs = stateMgr.getNodeReferences(id);
+        refs = refs.merge(changes);
+        if (refs.getReferences().size() > 0) {
+            return refs;
+        }
         return null;
     }
 
@@ -382,11 +397,11 @@
             // also put 'successor' and 'predecessor' version items to xaItem sets
             InternalVersion v = history.getVersion(name);
             InternalVersion[] vs = v.getSuccessors();
-            for (int i=0; i<vs.length; i++) {
+            for (int i = 0; i < vs.length; i++) {
                 xaItems.put(vs[i].getId(), vs[i]);
             }
             vs = v.getPredecessors();
-            for (int i=0; i<vs.length; i++) {
+            for (int i = 0; i < vs.length; i++) {
                 xaItems.put(vs[i].getId(), vs[i]);
             }
         }
Index: C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/version/VersionItemStateProvider.java
===================================================================
--- C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/version/VersionItemStateProvider.java	(revision 481177)
+++ C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/version/VersionItemStateProvider.java	(working copy)
@@ -19,6 +19,7 @@
 import org.apache.commons.collections.map.ReferenceMap;
 import org.apache.jackrabbit.core.ItemId;
 import org.apache.jackrabbit.core.NodeId;
+import org.apache.jackrabbit.core.PropertyId;
 import org.apache.jackrabbit.core.state.ItemState;
 import org.apache.jackrabbit.core.state.ItemStateException;
 import org.apache.jackrabbit.core.state.ItemStateListener;
@@ -41,11 +42,6 @@
 class VersionItemStateProvider implements VirtualItemStateProvider, ItemStateListener {
 
     /**
-     * the default logger
-     */
-    private static Logger log = LoggerFactory.getLogger(VersionItemStateProvider.class);
-
-    /**
      * The version manager
      */
     private final VersionManagerImpl vMgr;
@@ -128,13 +124,20 @@
     /**
      * @inheritDoc
      */
-    public boolean setNodeReferences(NodeReferences refs) {
-        return vMgr.setNodeReferences(refs);
+    public void addReference(NodeReferencesId refsId, PropertyId sourceId) {
+        vMgr.addReference(refsId, sourceId);
     }
 
     /**
      * @inheritDoc
      */
+    public void deleteReference(NodeReferencesId refsId, PropertyId sourceId) {
+        vMgr.deleteReference(refsId, sourceId);
+    }
+
+    /**
+     * @inheritDoc
+     */
     public boolean hasItemState(ItemId id) {
         return items.get(id) != null || stateMgr.hasItemState(id);
     }
Index: C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/nodetype/virtual/VirtualNodeTypeStateProvider.java
===================================================================
--- C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/nodetype/virtual/VirtualNodeTypeStateProvider.java	(revision 481177)
+++ C:/dev/jackrabbit/src/main/java/org/apache/jackrabbit/core/nodetype/virtual/VirtualNodeTypeStateProvider.java	(working copy)
@@ -17,6 +17,7 @@
 package org.apache.jackrabbit.core.nodetype.virtual;
 
 import org.apache.jackrabbit.core.NodeId;
+import org.apache.jackrabbit.core.PropertyId;
 import org.apache.jackrabbit.core.nodetype.NodeDef;
 import org.apache.jackrabbit.core.nodetype.NodeDefId;
 import org.apache.jackrabbit.core.nodetype.NodeTypeDef;
@@ -25,7 +26,7 @@
 import org.apache.jackrabbit.core.nodetype.ValueConstraint;
 import org.apache.jackrabbit.core.state.ItemStateException;
 import org.apache.jackrabbit.core.state.NoSuchItemStateException;
-import org.apache.jackrabbit.core.state.NodeReferences;
+import org.apache.jackrabbit.core.state.NodeReferencesId;
 import org.apache.jackrabbit.core.value.InternalValue;
 import org.apache.jackrabbit.core.virtual.AbstractVISProvider;
 import org.apache.jackrabbit.core.virtual.VirtualNodeState;
@@ -278,7 +279,13 @@
     /**
      * @inheritDoc
      */
-    public boolean setNodeReferences(NodeReferences refs) {
-        return false;
+    public void addReference(NodeReferencesId refsId, PropertyId sourceId) {
     }
+
+    /**
+     * @inheritDoc
+     */
+    public void deleteReference(NodeReferencesId refId, PropertyId prop) {
+    }
+
 }