Trevor - My site is currently in HTTP, is it possible that Google is denying my requests are part of their HTTPS push? ( I had something similar happen when I tried to use google location services )
Brenden - Thanks for this. This helped move the issue forward a bit, in that now I at least get error messages in the event log.
The remote server returned an error: (503) Server Unavailable.
Exception type: System.Net.WebException