Ok lets see if I got this right. the initial gmusic plays before anything else perfectly, then you go to other rooms and play other music. Returning to the initial music, it then plays it differently than the first time. Commenting out the other music, does the music in question play correctly every time? Does the other music make use of the same instrument in question? If so is the instrument aligned in the same channel as the first music? If you comment out the added music, then bring them back one at a time, do all of them cause the initial music's issue or is there on in particular that is causing it?