It's either corrupt at its source else, it's a hybrid avi format. You may need other codecs to play it or even try another player. Many people who dwnld lots of video material will not only hve xtra codecs but also have more than one player. Here's some codec sites: http://www.divx-digest.com/software/nimo_pack.html & also http://www.free-codecs.com/

Here's some wise words on players (click me)

Oh & not forgetting VLC a free player with in-built codecs plays almost anything

AVI Players: http://www.itzalist.com/com/avi-player-download.html
http://www.hyplay.com/free_avi_player_download.htm
http://www.karawin.fr/