The route is in the helper VM, i.e. the destination. See this KB in order to log in: http://kb.vmware.com/selfservice/microsites/search.do?cmd=displayKC&docType=kc&docTypeID=DT_KB_1_1&externalId=1036746
However the helper's start-up invokes "route add default gw GATEWAY". Since it has only one interface, the other command should not be necessary.
Please provide some feedback in case this workaround succeeds (and the usual way doesn't); I'd like to diagnose the issue and hopefully find a solution.