Ops, i'm using an unidirectional OneToMany relation with List and ArrayList (and i cannot change this). View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4217599#4217599 Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&p=4217599