Hello anonymous wrote : it was rather unexpected to lose the class without any traces. Not for us. This kind of functinality was never integrated in a production stable seam library. anonymous wrote : ut we try to use Seam in some kind of commercial development If this is the case why are you using Seam in its development form? Why not use the original Seam release. I am lucky since i have only a prototype now,:-) The difference between HibernateManagedEntity and ManagedEntity is the persistence Method. One uses an EntityManager and the other a Hibernate session. Ciao, Carsten View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3976978#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...