I haven’t been having much luck with video cards this year.
I purchased an inno Nvidia GeForce 7300GT a few months ago. And it worked fine.
Recently, I installed an intensive 3d screensaver (hyperspace from http://www.reallyslick.com/).
While it was running, I noticed that approx. every minute, My 22″ LCD display (1680 X 1050) would just go blank, for about 1 or 2 seconds, and than the screensaver would continue as if nothing happened.
My wife also installed “MyVirtualHome”, and that also caused the same problem (but even more frequently)
I figured: its either the video card about to fail, or the monitor about to fail.
To eliminate the video card, I tried another one (a GeForce 5500), but it seemed to struggle to display 1680 X 1050 (but 1440 X 900 worked just fine).
After some digging, I found a mention about some video cards not working well at high resolutions while using the DVI connection.
So I switched over to the (inferior) analog cable, and hey, problem fixed.
Now I need to find a well-shielded VGA cable, as the analogue signal is slightly “shaky”.