I believe I may have found my problem. By changing the PersistenceContext in my SFSB from this: @PersistenceContext(unitName="warehaus") | protected EntityManager em; to this: @PersistenceContext(unitName="warehaus", type=PersistenceContextType.EXTENDED) | protected EntityManager em; it now appears to be working without throwing an error. Apparently in 4.0.4.GA the PersistenceContext was extended by default, now it has to be specifically set as extended, I'm guessing? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4016714#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...