Help! Empty mp3's?

Well, I have many mp3’s on my computer, and have noticed recently that they seem to be emptying themselves out, or something. Songs that I had once fully enjoyed now are empty; still existing, but the file size says 2.13 kb’s on each one; they are all this size now! How can this even happen?
I have all my media on an external HD (a one-touch maxtor 80 gig), which I did last Christmas. Can this be the problem? I have run AVG on the maxtor, with no virus results, and am now running it against my entire system, but don’t think I’ll find anything. I tried googling for this but can’t find a thing. has anyone ever seen or experienced this themselves? I can only listen to two postal service songs now! And I think this has happened with a few other songs.
Along with moving my media, I recently downloaded this program called predixes music magic, which allows you to organize, edit tags, and make playlists from your music (it analyzes files to see which are similar so you can choose a song and create a playlist around it sort of). Could this be the problem? Anyone else ever use this?