Thanks! This was a great learning experience for me. We found that we had to "search and destroy" all classes of the package javax.jms from our application's third party jars and that fixed it. We also used Scott Stark's Debug class (source available on the net) and that was extremely useful for finding where classes were being loaded from. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4174011#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...