hi there
could you repeat the problem and collect the agent side debug logs? http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1017939
it is possible that the issue is on the zero client side, but I dont think that error message you flag is the problem. What is the network latency between the client and the guest? is it a reliable LAN link?
sorry - at this stage dont have any further suggestions, need to see logs,
cheers
peterB