It did sound suspicious. Yet my client referenced only 3 jar files two of which are JBoss's (jboss-j2ee.jar and jboss-messaging-client.jar). jboss-j2ee.jar is picked it up from jboss.home\client while jboss-messaging-client.jar is from jboss-messaging-1.2.0.sp1 installed directory. The 3rd jar is my application which includes the EJB beans. I opened this jar and it had no JBoss's classes in it. On the hand, I ran the jboss-messaging-1.2.0.sp1\example\stateless which did a sessionbean lookup and that ran successfully. Any idea? Thanks View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4034753#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...