My 600 often does a hard reset when I answer the phone, or when I turn the phone on and it does an AT&T network search. I thought that it was a battery problem, and have replaced the battery 3 time in 12 months. The problem seems to go away for a short time and then it starts again as it did this evening when answering the phone (new battery yesterday -- 2000mA).

Is this a firmware problem or what? Any ideas?