I have registered on this forum simply to help with this topic.
I have had the same problem in the past.
I found that the GPU (NVIDIA GeForce GTX 285) was overheating.
I have now cranked up the GPU fan from auto to 80% and the problem has never reoccurred.
I used the Nvidia system tools to perform the changes.
Hope this helps.
My System Information
Operating System: Windows 7 Ultimate 64-bit (6.1, Build 7601) Service Pack 1
System Manufacturer: XFX78I
System Model: XFX nForce 780i 3-Way SLI
BIOS: Phoenix - AwardBIOS v6.00PG
Processor: Intel(R) Core(TM)2 Quad CPU Q6700 @ 2.66GHz (4 CPUs), ~2.7GHz
Memory: 8192MB RAM
Available OS Memory: 8190MB RAM
Page File: 2145MB used, 14233MB available
DirectX Version: DirectX 11
User DPI Setting: Using System DPI
System DPI Setting: 96 DPI (100 percent)
DWM DPI Scaling: Disabled