Hi. AMD64x2,
I'm sure you've already tried but you could have a look at the graphics drivers, go to the the manufacturers site, (not MS, Windows update tends to lag behind), download and install the drivers. I only suggest this as the x64 driver situation is very fluid at the moment, and there may be new drivers available,
You could also try a system file check in case it's a windows glitch,
System Files - SFC Command - Vista Forums
Another thing to try is to check different image formats does it happen with .BMP or .TIF etc,