I just started having this problem, Ive got ffdshow installed and both media player and Media Center use ffdshow as a codec.
Now for some reason when I play avi (avi, dixv and xvid) on WMP it extremley dark, and only sometimes on MC. On WMP i havent found a solution. On MC I have to change to theater view and back to display a couple of times in order to get the brightness back to normal.
Ive uninstalled ffdshow a couple of times, Ive also uninstalled WM 11 codec. Ive tried other codecs like just divx, and cccp. and the problem is excactly the same, so its not the codecs.
Any help is greatly appreciated.