crenchy

When I open an mp3 file in WavePad, I can see the sine wave, the length of the track, etc., but when I click the play button, no sound comes out. The cursor moves along the sine wave as if it were playing sound, but there's no audio. And if I edit it, loop the selection, and save it as a new mp3 file, when I try to play that file in, say, Windows Media Player, it plays silence, even though it's showing that it's playing. When I play the original file in Windows Media Player, it plays fine and I can hear it. It's just not audible (at all, no matter what my volume settings are) in WavePad. Help!