I think I can understand this now. I believe it can be explained in a more simple use case: consumer A rolls back message M1 on Queue Q rollback is replicated delivery of message M2 on live to consumer B on Queue Q delivery is replicated rollback hits backup and M1 added to top of Q replicated delivery hits backup looking to find M2 on top of Q but instead find M1 View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4230179#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...