It works, if i use List bets = query.getResultList(); instead of List bets = query.getResultList(); I think its necessarily for marshaling. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3995276#3995276 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3995276