Background: I bought a $2499 MacBook Pro in October. I setup a boot camp partition with Windows XP Home which I only used for playing Team Fortress. Last week my MacBook Pro was stolen. I got a new one (same model) and installed Windows XP Home via boot camp. Everything seems to work perfectly, except that now after playing for a few minutes the computer hangs. The screen goes black, the audio starts looping (a short loop, less than a second), and the keyboard is unresponsive (although the backlight stays on). I have to hold down the power key to shut off the computer when this happens. The event log shows a system error saying that the ACPI BIOS tried to write to an illegal address. I tried disabling the ACPI battery driver in the Device Manager but it had no effect. I get this lockup every time I play TF2. Since that's the only reason I use Boot Camp, I'm hoping I can figure this out. I'm confused because the previous MacBook Pro did not have this issue. Any suggestions are appreciated!