This has come up several times before, and if I remember correctly, almost every time has been due to people sharing the session between multiple threads. JMS sessions are supposed to be used by only one thread at a time so this would be illegal. Can you confirm you're not doing stuff with the session with multiple threads at the same time? E.g. two consumers on the same session, and calling consumer.receive(..) in different threads, or two producers on the same session and sending conurrently on different threads? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4016307#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...