hey I can give you an advice so you can be able to see what's not corrupted from the avi file... ( I can't tell you why it's corrupted but may be it will help...) try to rebuild the index of the file with this program: DivFix. You can find it here ready for download 100% free: http://www.softpedia.com/get/Multime...d/DiVFix.shtml
It works every time... good luck.