I would bring this up on the Hibernate forums. This is pretty specific to them, since both data versions on the node are Hibernate classes: | org.hibernate.cache.OptimisticTreeCache$DataVersionAdapter | and | org.hibernate.cache.OptimisticTreeCache$NonLockingDataVersion | JBCACHE-806 pertains mainly to problems with the DefaultDataVersion shipped with JBC. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3997654#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...