Having a problem with games. Hard to explain. Screenshot in post.

[CLock3]

Hello everyone. As the title states, I seem to be having a problem when playing games, and I'm assuming it's related to the vid card. I started noticing it when I got Far Cry 2, and thought it might just be something with that game, but I recently got Fallout 3, and it does the same thing. Basically, the entire time I'm playing a game, I get a flashing/flickering on and off on the top of the screen, basically where the title bar would be if the game was windowed. I can't figure out what could be causing it. I've tried two drivers, the 178.13 on EVGA's site, and the 178.24 on nVidia's site (which I'm running now), installed after using Driver Cleaner and such. The problem is the same with both drivers. I also thought it may have something to do with my taskbar, as it's on auto-hide at the top of the screen, so I turned auto-hide off, moved the taskbar, everything, and the problem stays the same no matter what. I also thought it could even be something weird due to the XP theme I'm using, but it happens with any theme. Anyone have any ideas on what could be causing this?

Here are some screenshots to show what I mean (resized from 1680x1050):

And it does it really fast. It's not like an on for a couple seconds, off for a couple seconds thing. It's basically on-off every couple frames or something. Also, that spot in the upper right corner only occurred when I would capture the screen. I don't see it during gameplay, or it happens so fast that I can't. Otherwise games would be unplayable. It's annoying enough as it is, haha. Anyways, thanks in advance for any help.

EDIT: I'll try to get a short video of gameplay put up if that will help any.
EDIT 2: Actually, I guess I won't, haha. I took a couple using FRAPS and it doesn't show up in the videos, so the screenshots are all I got.

 

[kemekalx]

Have you tried booting your system with no background processes running?
I get weird flickering in some applications every now and then similar to what you describe. Turns out the cause was Norton Antivirus trying to display a dialogue box of some kind that was technically displayed but not actually visible on the screen for some odd reason.
Hopefully that makes sense, and can be of some help.