I too was having issues with Nvidia X 580 and full screen Guild Wars 2 killing the computer (no not shutdown from heat, it is like ripping the power cord out). I have tried both the beta and the stable drivers. My solution I am using now with no issues is stable drivers and windowed instance of the game. I can play for countless hours with this method. But once I go full screen, it is 10 minutes – 2 hours. I am running Windows 7/64 bit.