Index: server/src/ome/security/basic/MergeEventListener.java
===================================================================
--- server/src/ome/security/basic/MergeEventListener.java	(revision 971)
+++ server/src/ome/security/basic/MergeEventListener.java	(working copy)
@@ -91,6 +91,8 @@
 			HibernateUtils.fixNulledOrFilteredCollections(
 					(IObject)entity,(IObject)target,persister,source);
 			propagateHiddenValues((IObject)entity,(IObject)target);
+//			 BUGFIX TEMPORARY
+			revertValues((IObject)entity,(IObject)target);
 		}
 		super.copyValues(persister, entity, target, source, copyCache);
 	}
@@ -105,6 +107,8 @@
 			HibernateUtils.fixNulledOrFilteredCollections(
 					(IObject)entity,(IObject)target,persister,source);
 			propagateHiddenValues((IObject)entity, (IObject)target);
+//			 BUGFIX TEMPORARY
+			revertValues((IObject)entity,(IObject)target);
 		}
 		super.copyValues(persister, entity, target, source, copyCache,
 				foreignKeyDirection);
@@ -187,6 +191,14 @@
 		}
 	}
 
+	protected void revertValues(IObject from, IObject to)
+	{
+		if ( from.getDetails() != null && to.getDetails() != null )
+		{
+			from.getDetails().setCreationEvent( to.getDetails().getCreationEvent() );
+		}
+	}
+	
 	private void log(Object...objects)
 	{
 		if ( log.isDebugEnabled() && objects != null && objects.length > 0)
Index: server/test/ome/server/itests/ImmutabilityTest.java
===================================================================
--- server/test/ome/server/itests/ImmutabilityTest.java	(revision 971)
+++ server/test/ome/server/itests/ImmutabilityTest.java	(working copy)
@@ -69,8 +69,8 @@
 		
 		// This fails because it gets silently copied to our new instance. See:
 		// https://trac.openmicroscopy.org.uk/omero/ticket/346
-		// i = iUpdate.saveAndReturnObject(i);
-		//assertEquals( i.getDetails().getCreationEvent().getId(), oldEvent.getId());
+		 i = iUpdate.saveAndReturnObject(i);
+		assertEquals( i.getDetails().getCreationEvent().getId(), oldEvent.getId());
 		
 		// Saving and reacquiring to be sure.
 		iUpdate.saveObject(i);