Shoutbox

I have some AVIs compressed with XVID. The sound plays fine, but the picture just freezes on whatever frame the seeker bar selects. I've Googled this problem and downloaded a tool that supposedly fixes the problem, but it didn't work.

Any ideas?

Edit: This problem also occurs on my housemate's laptop, who I got the vids off.

Edit 2: Changed title to reflect actual problem.