I just upgraded to IE 8.0 on my developer machine and my screen started flickering. The first thing I thought was, "Well, it must be the IE 8.0; something must be wrong with it or some setting must need to be changed." So I searched throughout the internet looking for a proper diagnosis. 

Then I looked at my refresh rate to make sure it was compatible with my video driver. On and on I went to no avail until I finally was looking at replacing the video card. So I crack open my machine and take out my old video card. When I looked at it, I thought that it sure was looking mighty dusty around the fan and the heat sink. So I grabbed some canned air, cleaned it up and put the card back in the slot where I got it from. Well, no more flicker! The screen is working just as expected.

Moral of the story is: "a clean computer is a happy computer...and an even happier owner!".