When I play certain avi-files, the left side of the video will have bars about 4-5 pixels wide on every other horizontal pixel line (i.e. they're 1 pixel high and 4-5 pixels wide). It is obvious when watching scenes with high contrast in between the left and right half of the video that the bars correspond to the ones in the right side of the video (they show the same as the pixels on every other horizontal line on the right side of the video).
This doesn't happen with all avi-files and in some, the bars are white and doesn't change at all. I've reinstalled the k-lite codec pack twice, but it didn't help. The problems only occurs in WMP when using ffdshow. The video works fine in VLC.
I'm suspecting an interlacing problem but I can't find any solution anywhere.
Any suggestions?