There was a thread on this from July but I'm unable to reply to it anymore so here goes.
http://communities.vmware.com/thread/411610
I would also like an answer to this. The problem seems to be with DistributedSystem.connect which can only be called once (or it throws IllegalStateException) but there is no way to check whether it's been called already.
java.lang.IllegalStateException: A connection to a distributed system already exists in this VM. It has the following configuration:
ack-severe-alert-threshold="0"
ack-wait-threshold="15"
What is the proper way to detect an already initialized DS?