I don't know. It´s pretty brainless thing to do, but of course if it´s only way.

I don´t have right now any other idea except to connect phone to pc, remove all songs (don't delete .sounds directory there is ring tones also IIRC), plug off from computer, shut down it (btw. do you have extra memory card in phone if so take it off), turn it on, connect pc, put couple of songs, plug off from pc, try to play them and see if it is still happening.