I try to explain a little more. Our system has two interfaces, a web-ui and a messaging based interface to another system. Messaging requests come this way: MessageController (MDB) -> Core (SLSB and Entities) -> DAOs (SLSBs) -> Hibernate UI requests go the other way: Web-UI -> Application (Seam components) -> Core -> DAOs -> Hibernate DAOs use entity managers injected by "@PersistenceContext". I cannot use @In because otherwise the messaging scenario wouldn't work. For messaging requests I need a transaction-scoped PC which I get for free by the default EJB PC propagation. For the Web-Client requests I need a conversation-scoped PC. I thougth I could simply attach a SMPC or BMPC to every transaction (EntityManager.joinTransaction) in the application-layer and do not have to change the layers below. Maybe there is not such a simple solution. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4069692#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...