First off, I'll say that I am not sure which category this belongs under as I am stumped on what the problem could be. I decided on hardware since the error message that I see for a split second mentions the Asus AI Nap (I THINK....)
I can run my computer for days without a problem and can usually play Call Of Duty 5 without an issue for hours on end. However, every once in a while (maybe one or two days a week), and only while playing the game so far, the game will appear to freeze for about a second, then go black and minimize to my desktop where I see a somewhat lengthy error message. I've never been able to read more than the first line of it but I think that I've seen Asus Ai Nap mentioned in the body of the message. It does not look like a typical Window's error message. The first line of the message reads "The power button configuration settings...."
After a split second my PC shuts down completely. I can boot it right back up and everything loads and runs like normal. When this happens it tends to repeat itself again soon after sometimes more than once. Today I ran the game for about 6 hours, afk half the time but still running, and then it shut down. I started back up and went back to playing and it happened again within the hour.
I think I can safely rule out overheating as my cooling is about as good as it can get without going with a water cooler. My CPU usage in game barely reaches 15%... I even ran for months overclocked from 2.66 to 3.8 without any heat issues and I'm back to 2.66 now.
Again, this has only ever occurred while playing the game...
I have never used AI nap or any of the asus software other than the Fan Xpert. The whole Asus AI Suite is installed in order to use Fan Xpert along with TurboV, PC Probe II, and AsusUpdate.
I have Vista Ultimate 64...
Here are some spec copied from my profile... I can furnish any other necessary information.
-Cooler Master Storm Sniper Mid-Tower case w/ 2x 200x30mm, 2x 120x25mm fans
-Core i7-920 OC'd to 3.8
-Asus P6T Deluxe V2 Mobo
-Cooler Master V10 Hybrid TEC
-Western Digital Caviar Black WD5001AALS 500GB 7200 RPM 32MB Cache SATA
-Cooler Master UCP RS700-AAAAA3 700W PSU
-6GB (3x2048MB) OCZ DDR3 PC3-12800 Intel® i7 Triple Channel
-Sapphire ATI HD 4850 512MB GDDR3 PCI-E graphics card
-Samsung Syncmaster P2370 23' 1920x1080 LCD Monitor
-Logitech G15 keyboard and G9 Laser Gaming Mouse
Edit: I just remembered, I updated my BIOS to the newest firmware to solve a BSOD problem that I was getting also only during gameplay. That problem was solved but this one has since started.
Edit 2: I removed all asus software and the problem persisted. I get the same shutdown, I just don't have the game minimize to desktop at the last second just to see an error message I can't read. Instead, screen goes black and everything shuts down.
This leads me to believe that the error message I was seeing was caused by the shutdown and minimized the game just prior to everything shutting off rather than actually causing it.