@kraus: I've noticed that this bug still hasn't been fixed. The problem is that the event for a script being closed, or WLM being exited is not always triggered, so Mute doesn't notice, and doesn't unmute sounds. And the next time it starts, it doesn't know sounds are muted. But I already know how to fix this for good. Don't worry.
@CanadianOriginal: At one point, I'll run out of features to add to this script, and I'll implement your suggestion. But for now, I have other things to do. Sorry. It will come though.