Try this player VLC http://www.videolan.org/vlc/ (choose nearest mirror site) & if the same thing happens then it's a problem with the file. If not, then it sounds like you need more updated codecs. (By the way, VLC has built in codecs & plays everythings except the odd wmv file.)

Codecs: http://www.divx-digest.com/software/nimo_pack.html (Mirror site 2 only) OR http://www.click-now.net/html/K-LiteCodecPack.htm