This smacks of a firewall issue, I thought you'd said you weren't using one but now I read back your emails I can't see anywhere where you say that. Are you running a flrewall or any iptables rules on any of the nodes? It looks to me like you may have some setup from on the worker nodes.
Ashley. -- Ashley Pittman, Bath, UK. Padb - A parallel job inspection tool for cluster computing http://padb.pittman.org.uk
