Screen goes weird after few minutes of Xvid Avi Playback

I just reinstalled my machine and all the drivers software etc, and now when I play an Xvid avi file, after around five minutes, the bottom two thirds of the screen just consists of vertical lines, while the top third looks fine. The bottom portion looks like someone grabbed a row of pixels from the top and stretched it downwards.

ANy idea what the problem is? I'm using the xvid 1.1 codec, and the latest nVidia driver (84.21), which would be the only difference from my previous install which was using much older drivers. Could this be an issue and how can I fix this? I also wanted to add that this does not happen during gaming or any other task - only with avi playback. And once this happens, even if I close the movie thats playing, the windows desktop also remains the same until I restart

 

To add to my previous post and after a few hours of tearing my hair out, I noticed this happens only with media player classic 6.4.9.0, which I usually use. When I play with the regular windows media player this problem does not occur. any ideas on this?

 

Ignore my previous post, this happens even with Windows Media Player 10 and VLC. I hope I'm posting in the right forum as I'm not sure if this is a hardware or software issue.

 

Is there anyone who can help me? I've tried everything from reinstalling the machine three times to changing players and codecs but this still happens. Please help!

 

Last two days the screen pattern has now changed and instead of the stretchy lines I mentioned I get either a blank screen, grey vertical lines, or a light blue screen. Please if anyone can point me in the right direction it would be much appreciated, Is this a hardware issue (say with teh graphics card) or a saftware issue? The only change in my system is an addition of a new western digital raptor drive, and these problems are happening after I have reinstlalled the machine on the new drive.

 

looks like i have to answer my own questions here problem resolved when I installed the drivers that came with the video card - MSI 66.81. Not an ideal solution as I would still like to use newer drivers without having video problems...