it could be that whatever type of model or perhaps skin or detail of that uboat is causing your video card to try to draw more power or even your cpu to draw more power from your power supply and it shuts down because it gets hot. or its pulling too many things and your cpu runs hot causing the system to shut down. or you have a bad chipset heating up somewhere causing the shut down. another words.... its a heat issue somewhere in your system, something is heating up and just shutting down.
few ideas to think about. hope it helps. good luck. another good idea is to post your system stats so we can evaluate your problem more closely
