Help me with avi video pixelation.

Hi all,
I usually play avi files without any problems. However, now some files are pixelated specially in full screen. I've updated the video drivers, directx and codecs but I got no result. I've tried to play the files on other media players . Now I can not enjoy my movies smoothly as all of them are an avi format. Please help me with this avi video pixelation.
I have updated the doc. This is the post which I want to update. I have given you the url as well.
