Messed up screens whilst watching videos.

Hi there,

I wonder if any of you could help me with the problem I've had for the past 4 months. Basically, sometimes when I play a video, the video won't play where it's meant to, but play diagonally to the right of where it's mean to play, but in a smaller screen and often doesn't play the file right so you see no picture. This happens all the time in Windows Media Player, sometimes in DivX, most of the time in Quicktime, and never in Winamp.

Now I'm thinking it's mostly a software problem, because if it was a Graphics card problem then why wouldn't it do it all the time.

Anyway, hope that I can a some help on this. Cheers.