Gordon,
you are right that I confused Persistence Unit and Persistence Context. Both Session Beans are not acting within the same transaction.
When I said previously "... the EntityManagers refer to the same persistence context ...", this was because both stateless session beans share the same Persistence [b]Unit[/b], as both beans contain the following EntityManager declaration with the identical "unitName" attribute:
@javax.persistence.PersistenceContext(unitName="backoffice")
private EntityManager em;
As Marina suggested, I read "5.6 Container-managed Persistence Contexts" in the JPA spec. I really do not understand it fully, but I came to the conclusion that for my application it is not a good idea to have two session beans with two entity managers, because of the observed effects. I did implement it this way purely for cosmetical reasons, to separate actions that a normal user can initiate from actions that an administrator can initiate. Both session beans operate on the same entities, and to avoid the effect of the separate caches I will merge them into one bean.
Regards
Stephan
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