i did it. these methods must be into different persistence context ( into different session beans) Thank all of you anyway. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4107648#4107648 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4107648