Main Mp3 player won't play all Mp3s

Sorry guys I may be a pain in the neck with so many questions (and I have many more for sure!)but we must keep this forum moving a little. Why the main Mp3 player can play some Mp3s and can't play others? I played all the Mp3 in the desktop opening them with a different player (it says MPLAYER) inside the MS. I don't see any difference among all the MP3.
Thanks.

Windows media files will not play in the main kaoss player, but will play in the MPlayer...If you look to the left side of a song in the main player there will be a note or other mark that tells you it will play..otherwise use the MPlayer for the unmarked songs..

Likewise the CDG songs will not play till the new player update..

You can convert the WMA to MP3 and they will play fine in the main player..

you are running the OLD OS 2.8, the players not include the all media format.
All are working from OS 3.2: http://www.lionstracs.com/store/ms-os-32-p-227.html

# MEDIASTATION SYSTEM OS :
# Totally changed the Audio MP3 Players engine library, included now the Hig quality LIBMAD for the Mpg support.
# Totally changed the Audio WAV Players engine library, included now the LIBSNDFILE for the Wav, FLAC, AIFF.
# NEW MS Players able to play now the following file formats: wav, ogg, flac, aiff, aifc, au, snd, raw, paf, * iff, svx, sf, voc, w64, mat4, mat5, pvf, xi, htk, caf, sd2.

Hey guys I know what a WMA,Wav, Aiff etc.. are. I am talking about MP3. I only want to play MP3 and some of them didn't work. I checked their "properties" in the MS and in my PC and it says they are MP3.

[This message has been edited by vagro (edited 08-12-2009).]

I reloaded the Mp3 files that didn't work and I can listen to them now. May be the files were corrupted when I copied them the first time.
Problem solved now