One of the two phones I got via NG was married, so if I left it alone, it rebooted itself. Interesting fact: following a reboot, a beep can be heard, although on properly functioning devices, there is no such noise. I made a phone purchase from M. Video, and after 14 days, I returned it. It took two months of drama to give over for repair and collect up from repair. The problem was finally fixed, though, after I contacted Samsung's official customer service. The result was a new motherboard and batteries.