Windows Media Player - slow mo

[soundtest]

Sometimes when I play back .avi's or windows media files in Windows Media Player (latest version), the playback is like it's in slow motion... audio and video. I play the same file in BS Player and it plays back fine, so I don't think it's a codec issue or an issue with the file itself. Anybody encounter this?

[AChimp]

It does sound like a codec issue; just that Media Player isn't using the codec properly.

Or maybe there's an option setting somewhere for play speed. :/