All *.avi and *.mpg zoom in

[Crowmeister]

I've got a really weird problem since last week
All of a sudden all my *avi and *.mpg movies zoomed in in the top right.
So you only see about a quarter of the screen.
Also the screen is really blurry and it's shaking a bit (not much) as if it was filmed by an amateur.
The problem occurs to all codecs so it's not a matter of codecs.
And the Quick Time (*.mov) and Real Player (*.rm *.ram) movies are fine

I tried 3 different players (WMP, Divx player and BS Player)
I download 3 new codec packs (Tsunami, Nemo and ffdshow)
But I do not think it's a codec problem because it occurs to all codecs, so it would be weird that all of a sudden all of the codecs (and MPGs) have the same problem
I also downloaded some new detonators for my GF 4 4200.

All of the above did not help and did not make it worse.
So does anybody know of a solution?

By the way I could make a screenshot (if I knew how to make one of a movie) and post it, if that were necessary

[Crowmeister]

I just found out that Real Media Movies have the same weird problem as the others
That would mean it's Graphic Card problem right?

[Crowmeister]

bump
still haven´t fixed it
do I need to format ?