Screen Flicker on XP Desktop

Just recently my desktop image starts to flicker after a few minutes affecting the bottom 2/3 of the screen. At this point no driver, software or hardware changes had been made. I checked all leads and the problem recurred after swapping the DVI to analogue on my TFT. I changed my Radeon 8500 to a 9600 and it’s still happening still just affecting the desktop image (standard or XP plus image) and I have to turn the monitor off and then on again to be able to click on any of the my icons. The TFT is set a 1280X1024 at 60Hz as it always has been.