I'd have to agree with FrotzFactor. Ports tend to be glitchy, especially during the time this was made.
I read somewhere that the game wouldn't work on modern PC's unless you disabled explorer.exe while the game is running, which means that if the game crashed or once you quit the game you would then have to restart your PC if you wanted to do anything else on it. Good job on the part of GOG for getting around this. Considering that, gives you an idea of how rough the compatibility of the porting went. I doubt anything can or will be done about this bug.
I sometimes wonder what is more annoying: the music abruptly cutting out? Or some of the less than atmospheric music tracks droning on and on. Personally, I enjoy the intermittent quiet.