"bstansberry(a)jboss.com" wrote : I thought PojoCache already required the pojo to implement Subject, and that the mixin was being added via your standard pojocache-aop.xml transformation? So, it's just a matter of the session registering as an Observer. That's a PITA, but its a PITA that's already implemented from 4.0.x, so no big deal. OK, are you aware that PojoCache has its own class of Subject and Observer then (o.j.c.pojo.observable.*)? Make sure you subscribe to that instead. Reason is becuase I need to piggyback information such as field and pre and post events as well that are not present in the AOP package. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3987519#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...