Why are you being bounced to AT&T or HTC for a problem with your N800? That's bizarre... are you sure you're getting through to the right people at Nokia or maybe it's one of their third-party support outfits who think you have a phone rather than a tablet. As for support... to be honest, this is it (this forum, or there is also the "users" mailing list but that isn't as accessible as a forum). The usual solution to problems that can't be solved within a short while is to take the N800 back and get a replacement, and if it's still a problem them maybe it's not for you. As for your Cingular problem - try reading this thread and see if it fixes your cellular connectivity problem. There is a misconfiguration in the current firmware which is very easy to fix.