Today seems to be my release day!
Just released a new enhanced version of GMobileSync (1.3.6) which now has Proxy Support as well as a few bug fixes.
One major bug was due to Who.Rel being a required property since of late on GData API. GMS had not implemented this property before but since our last release updating GCal was failing since Who/Rel was made a required parameter. That is now fixed with 1.3.6 so your syncs should work like a charm!
Go ahead and grab yourselves the latest release and be in Sync with your WM Devices and GCAL!