I'm currently having and issue where after having been on for a few hours my monitor will periodically begin resetting, first in slow intervals and then gradually increasing in frequency until it resets every few seconds. Sometimes it will even turn off completely and say "No Signal" until I alt-tab at which point it will turn on again. This leads me to believe that it is some sort of video card issue.

To give you some background I have an Acer AL2216W 22" LCD which has served me faithfully for the past two years or so. My video card is a nvidia 8800 GT, and I recently upgraded (monday to be precise) my computer to a Core i7 920, Gigabyte GA-EX58-UD3R, and 6gb of OCZ PC3-1600. I have 3x WD 640gb hdds and a 650w Antec PSU. My OS is Vista Ultimate x64 SP2. No overclocking and temperatures are CPU: 41C, Case: 35C, and GPU: 64C. I have yet to play any games on it or stress the system. Mostly I've just been installing updates . All my drivers are currently up to date.

The first time I encountered this problem was on Tuesday after installing SP1, but I doubt that has much to do with it, and further updates didn't seem to affect it much. Restarts did nothing to slow down the frequency of the monitor resets, and only when I turned off my computer for half did they seem to go away before coming back after a few hours of use. I checked the voltages of my 12v rails and they came back as a nice 11.9v.

I'm quite stumped as to the source of this problem and what to do to fix it. Any help would be greatly appreciated.