My Iphone 2g (3.1.2) randomly reboots on applications start up. It is all random. Sometimes it is a day without any reboots. Some time it occurs is 3-4 times a day. The "reboot appictions" allways random. And this "reboots" are not connected to any of them specially. Just when you touch any app. icon screen flashes (sometimes with with horizontal line) and then the device reboots. The device works perfectly. No other glitches. No water inside. "Touch" works all and full. Screen have no problems and even no scratches. I tried to backup the deivice with ipsw , but the situation did not changed. Please advice.