It happens with my N95-3 and N95-4, not sure exactly what other Nokia phones it affects. I believe the 6650 also, but I guess what happened is that AT&T "upgraded" their network, "optimizing" it for the iPhone and in doing that, for some reason, causes Nokia phones to constantly reboot. Maybe has something to do with overlapping 850 and 1900 frequencies? I read that upgrading the firmware to the latest kinda fixes it, but I don't think it's a guaranteed fix.
Gotcha. Thanks for the explanation. Doesn't affect me, hopefully it doesn't affect the N8. =)