A free source or Open Source program that is recommended by Mac users on another forum I visit is
VLC Media Player for the Mac OSX........ Being open source, it is free and they haven't found anything it won't play... they indicate preferring it over WMP by a large margin, especially liking that you don't have to worry about getting all the latest codecs for the Open Source program ....
http://www.videolan.org/vlc/download-macosx.htmlYou can read about it at the link provided, and may decide to download it and give it a try...... Hope that helps...
Here's the M$ link for their WMP version 9 for the Mac OSX....
http://www.microsoft.com/windows/windowsmedia/player/mac/mp9/default.aspx...... Didn't see any mention of the "Stuff It" program listed at this site.... could you have been using a 3rd party site that wanted to slip in the "Stuff It" program, rather than the Micro$oft site?