Doesn't happen 100 percent of the time, and haven't noticed it with other games, nor with the 32 bit client. Only happens when in true full screen mode, not windowed. I've noticed a huge performance increase with the 64 bit client, and would love to continue using it. Once when I was just trying to lower the resolution, and a few times when alt-tabbing over this last week, will cause bsod and my system restarts. I created a fresh game consultant report and can attach the dmp file too if necessary. Thank you in advance for any help.