ifox, you're not alone! It's just that most people don't realize it. If you have setup GMail as MfE (Mail for Exchange,) it should work normally, that's cause it runs directly between the server and your phone, however if you setup GMail from Google accounts on the phone, then there's a Nokia sync server involved in between your phone and the GMail's server. Occasionally, Nokia does maintenance on this server (service goes out for a few minutes) and you loose your connection to the server. Just restart your phone, that'll solve your issue.

Sorry about beating around the bush, before giving the solution..