Index: jackrabbit-core/src/main/java/org/apache/jackrabbit/core/BatchedItemOperations.java
===================================================================
--- jackrabbit-core/src/main/java/org/apache/jackrabbit/core/BatchedItemOperations.java	(revision 645007)
+++ jackrabbit-core/src/main/java/org/apache/jackrabbit/core/BatchedItemOperations.java	(working copy)
@@ -253,7 +253,7 @@
         int ind = destName.getIndex();
         if (ind > 0) {
             // subscript in name element
-            String msg = "invalid destination path (subscript in name element is not allowed)";
+            String msg = "invalid destination path: " + safeGetJCRPath(destPath) + " (subscript in name element is not allowed)";
             log.debug(msg);
             throw new RepositoryException(msg);
         }
@@ -302,7 +302,7 @@
 
         // 3. verify that source has mixin mix:shareable
         if (!isShareable(srcState)) {
-            String msg = "Cloning inside a workspace is only allowed for shareable nodes.";
+            String msg = "Cloning inside a workspace is only allowed for shareable nodes. Node with type " + srcState.getNodeTypeName() + " is not shareable.";
             log.debug(msg);
             throw new RepositoryException(msg);
         }
@@ -312,14 +312,14 @@
         NodeId destParentId = destParentState.getNodeId();
         if (destParentId.equals(srcId) ||
                 hierMgr.isAncestor(srcId, destParentId)) {
-            String msg = "This would create a share cycle.";
+            String msg = "Cloning Node with id " + srcId.getUUID() + " to parent with id " + destParentId.getUUID() + " would create a share cycle.";
             log.debug(msg);
             throw new RepositoryException(msg);
         }
 
         // 5. do clone operation (modify and store affected states)
         if (!srcState.addShare(destParentState.getNodeId())) {
-            String msg = "Adding a shareable node twice to the same parent is not supported.";
+            String msg = "Adding a shareable node with id (" + destParentState.getNodeId().getUUID() + ") twice to the same parent is not supported.";
             log.debug(msg);
             throw new UnsupportedRepositoryOperationException(msg);
         }
@@ -413,7 +413,7 @@
         int ind = destName.getIndex();
         if (ind > 0) {
             // subscript in name element
-            String msg = "invalid destination path (subscript in name element is not allowed)";
+            String msg = "invalid copy destination path: " + safeGetJCRPath(destPath) + " (subscript in name element is not allowed)";
             log.debug(msg);
             throw new RepositoryException(msg);
         }
@@ -514,7 +514,7 @@
 
         // check precondition
         if (!stateMgr.inEditMode()) {
-            throw new IllegalStateException("not in edit mode");
+            throw new IllegalStateException("cannot move path " + safeGetJCRPath(srcPath) + " because manager is not in edit mode");
         }
 
         // 1. check paths & retrieve state
@@ -527,7 +527,7 @@
                 throw new RepositoryException(msg);
             }
         } catch (MalformedPathException mpe) {
-            String msg = "invalid path: " + safeGetJCRPath(destPath);
+            String msg = "invalid path for move: " + safeGetJCRPath(destPath);
             log.debug(msg);
             throw new RepositoryException(msg, mpe);
         }
@@ -573,7 +573,7 @@
         } else {
             // check shareable case
             if (target.isShareable()) {
-                String msg = "Moving a shareable node is not supported.";
+                String msg = "Moving a shareable node (" + safeGetJCRPath(srcPath) + " ) is not supported.";
                 log.debug(msg);
                 throw new UnsupportedRepositoryOperationException(msg);
             }
@@ -629,7 +629,7 @@
 
         // check precondition
         if (!stateMgr.inEditMode()) {
-            throw new IllegalStateException("not in edit mode");
+            throw new IllegalStateException("cannot remove node (" + safeGetJCRPath(nodePath) + ") because manager is not in edit mode");
         }
 
         // 1. retrieve affected state
@@ -1104,7 +1104,7 @@
 
         // check precondition
         if (!stateMgr.inEditMode()) {
-            throw new IllegalStateException("not in edit mode");
+            throw new IllegalStateException("cannot create node state for " + nodeName + " because manager is not in edit mode");
         }
 
         NodeDef def = findApplicableNodeDefinition(nodeName, nodeTypeName, parent);
@@ -1226,7 +1226,7 @@
 
         // check precondition
         if (!stateMgr.inEditMode()) {
-            throw new IllegalStateException("not in edit mode");
+            throw new IllegalStateException("cannot create property state for " + propName + " because manager is not in edit mode");
         }
 
         // find applicable definition
@@ -1750,7 +1750,7 @@
                         // or an ancestor thereof
                         if (id.equals(destParentId)
                                 || hierMgr.isAncestor(id, destParentId)) {
-                            String msg = "cannot remove ancestor node";
+                            String msg = "cannot remove node " + safeGetJCRPath(srcPath) + " because it is an ancestor of the destination";
                             log.debug(msg);
                             throw new RepositoryException(msg);
                         }
@@ -1768,7 +1768,7 @@
                     }
                     break;
                 default:
-                    throw new IllegalArgumentException("unknown flag");
+                    throw new IllegalArgumentException("unknown flag for copying node state: " + flag);
             }
             newState = stateMgr.createNew(id, srcState.getNodeTypeName(), destParentId);
             // copy node state
@@ -1808,7 +1808,7 @@
                         if (stateMgr.hasItemState(mappedId)) {
                             NodeState destState = (NodeState) stateMgr.getItemState(mappedId);
                             if (!destState.isShareable()) {
-                                String msg = "Remapped child is not shareable.";
+                                String msg = "Remapped child (" + safeGetJCRPath(srcPath) + ") is not shareable.";
                                 throw new ItemStateException(msg);
                             }
                             if (!destState.addShare(id)) {