if you are still under warranty i'd get a new one instead of trying to deal with it by unlocking. You can still unlock the new one, but at least you know its not a real issue
You think so? You guys never get random reboots? On 4.0.2 it used to reboot when the phone had been on for over a week or so and I unlocked to Camera but that seems to have stopped on 4.0.4. I always just assumed I had installed something which fucked something up.
It's not too common, but it does happen, once a month or so.