Did you find some solution to this problem? I had my application working pretty fine catching a EntityExistsException and throwing my own @ApplicationException exception in JBoss 4.2.3. Now that I upgraded to JBoss 5.1, the same code does not work anymore, I'm unable to catch neither EntityExistsException or ConstraintViolationException. Do you (or somebody else) know what can I do? I would really like to use JBoss 5 instead 4.2.3, but this problem is annoying me. Please help! View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4237945#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...