I've had the phone since before it was 'officially' announced, and the only time it has randomly rebooted on me was today actually.. I was typing a text message and it just restarted lol. I might have hit the power button on it, but I don't think I did.
happened to me all the time, usually at night. It started happening during the day after a week. I took it back and got another one from target, no problems at all. People said get a new SD card and other things but just get a new phone. I tried everything to fix it.