Media Player

Hi!
I have recently installed the new Media Player 7 Beta version. I followed the instructions and all works very well. It is a great improvement over previous versions. However here is my problem. Although the box is ticked for the player to be able to play MP3’s it always tries to find Winamp player and says that it can not play the file through the existing player. But the documentation on the player says that it can.
I would very much appreciate some help with this matter.
Thank you very much in Advance,

George Gordon