"estaub" wrote : | | I don't have an answer, but I do have a little info. | The CGLIB proxies are used by Hibernate. | | http://www.hibernate.org/hib_docs/reference/en/html/performance.html#perf... | | Ah, this makes perfect sense. I was fully (ok, not fully) aware of Hibernate's us of proxies created by CGLIB. I was unaware of this quirk though. Looking back through all my personal use of hibernate, by public API's are always defined as interfaces, so sub-classes are actually sub-interfaces, and are therefore always castable (because the proxies can implement all interfaces) -- so I've never ran into this particular problem, although I've used Hibernate with polymorphism quite a lot. It seems the only real fix is for jBPM to re-design their public interfaces such that they are actually interfaces. Hence TaskNode would implement Node and not extend Node. This leaves me in an interesting quandy: no way to examine the Tasks of my process definition's TaskNodes. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4021379#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...