As part of the investigation of this issue, and per what you said about producers, I have found this other one: anonymous wrote : http://jira.jboss.com/jira/browse/JBMESSAGING-809 It has to do with sending messages now. It's a rare event but it can happen if you crash the server under high load. (>30% of probability on MultiThreadFailover if you have numberOfThreadConsumers>numberOfThreadProducers). (you have two properties you can change for these number of threads on MultiThreadFailover) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4010472#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...