Codecs Problems

I have a lot of mp3 music files that were provided to me and my problem is that Windows Medial Player will not recognize all of it. I thought is was a Codec issue so I tried Shark007 Codec Application V5.5.5. I am also trying to play the same Music in Zune and it doesn't recognize it either (unless I am still using the Shark SW incorrectly). It could be a few files out of a complete CD that don't work. Most of them are MPEG-1 Audio Level 3 codec. Some work, some do not. Here is the big BUT, they all seem to play in Quicktime without any problem, so the files don't seem corrupt.

Any ideas how this can be fixed? Thanks

WMP sucks if I'm honest, VLC Media Player is probably the best solution, even if the files are out of the CD (.cda), VLC can play it.

http://www.videolan.org/vlc/

Thanks for the info on the media player, this definitely worked as I can now play the file, however I still cannot get it recognized in the Zune SW so I can load it on my Zune HD.