An additional wrinkle if you're following along at home:
The java.rmi.server.hostname property also needs to be set in the JVM config of each instance. I've tested hardcoding the value in a cluster config and it works. Supposing it will work with per-instance substitution but not yet tested.
[Message sent by forum member 'gjwiley' ]
http://forums.java.net/jive/thread.jspa?messageID=373383