I think Sonic's MyDVD can fix it. But, you'll still have a broken DVD-readable movie. Was it a downloaded file BTW? If it was, did you let it download all the way, or did you rush it?
GOM Player claims that it plays broken AVI files so give it a shot. It has codecs built-in, so I just use that player instead of looking for all the codecs and codec packs or what not.... www.gomplayer.com