Sorry, but without knowing more details about the relationships among your classes in the various jar files, I really cannot answer your last question. There is something you might try to learn a little more about what is going on: start the JVM passing it the -verbose:class option. This causes the JVM to state where it found each class. Sometimes looking that this output clears up what is going on, especially if you see a class being loaded from an unexpected location. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4020830#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...