Index: jackrabbit-core/src/main/java/org/apache/jackrabbit/core/NamespaceRegistryImpl.java
===================================================================
--- jackrabbit-core/src/main/java/org/apache/jackrabbit/core/NamespaceRegistryImpl.java	(revision 643486)
+++ jackrabbit-core/src/main/java/org/apache/jackrabbit/core/NamespaceRegistryImpl.java	(working copy)
@@ -213,6 +213,7 @@
                     } else {
                         map(prefix, uri);
                     }
+                    map(Name.NS_EMPTY_PREFIX, Name.NS_DEFAULT_URI);
                 }
             } finally {
                 in.close();