You know what bug still pisses me off, after all these years?

to the above: it'll only do that if there's a music change when the game window isn't focused. apparently the sound code doesn't work for whatever reason if the window is switched. it's probably disabled whenever the window is unfocused in order to prevent it from making sound while minimized, and a side effect of this is losing control of the sound settings in favor of the defaults until you change them again or another music change occurs.