[juppy]

Possibly. Have you tried downloading the latest drivers for the 6600? And if those aren't solving the problem, have you tried some of the older drivers for it? I had an nVidia card awhile back that wouldn't run on the newest driver update and it would make the screen black out for a couple seconds when trying to scroll down the page. I had to go get one of the older versions of the driver for it to work right. Not saying that's absolutely it, just that you might want to try some of these non-cost things before you delve money into different hardware.