problem playing movies

[.slicer]

lately i've been having problems playing divx and xvid movies on my new laptop (dell inspiron 8500). When I play a movie the top right quarter is only displayed, but it is stretched to fill the entire player:

e.g.
for a movie:
|1|2|
-----
|3|4|
i get:
|2a|2b|
--------
|2c|2d|
in my player. (so i don't see 2 4 times, but 2 is just stretched to fill the entire screen).

I have this problem using bsplayer, windows media player, divx player. so i suspect it has something to do with the codecs. i tried uninstalling everything, and reinstalling but to no succes. I'm getting pretty desperate here, so any help would be appreciated.