I made a thread a few days ago which you can find here: http://forums.macrumors.com/showthread.php?t=904273 But the problem, slightly different has happened again. I thought I'd open a new thread. I was playing the same game, and the screen flickers before shutting down a few seconds later. I then press the power button and nothing happens. I press it again and the fan turns on and goes CRAZY for about a minute before the computer boots successfully. I hope nothing has crapped out. Thanks.