Which line of your code generated the exception? Is this line a typo: em.persist(em); (should read em.persist(tm);) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3958515#3958515 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3958515