Hmm, not including the MarshalledValues patch in CR3. It needs more thought. My current implementation calculates (and caches) hashcodes off the deserialized instance, so when this is replicated, if the key in an attrib map is a MarshalledValue, then hashcode() is called when putting this key in a node and this forces deserialization. Beats the purpose of lazy deserialization as well as re-introduces the need for region-based marshalling since this deserialization is done by the JGroups thread that deals with the incoming replication rather than a user thread on the remote cache. Note that this is only with using MarshalledValues to wrap keys. Works fine for values. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4119653#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...