I changed the sound device to SigmaTel Audio, curious if it will be any better. Now I can't change it back though, and it makes FamiTracker close every time I open it! What am I to do?
Try to start famitracker with the switch /unregister. If that doesn't work then you'll have to find the registry key and delete it: HKEY_CURRENT_USER\Software\FamiTracker.
But the latest version should restore default settings if it couldn't start.