I wonder there may be a portability issue for clustering if you cache home objects.
I mean it may be ejb server dependent.
I've ever failed to work a service locator with cache for WebLogic 5.1.
Since it was so unstable, I finally removed the cache feature from the service locator.
I'm not sure it was a bug or not.
I'm afraind I don't have experience with the JBoss clustering feature.