does any audio work inside MP? or is this just music?
you have reason :sorry:It really does sound like a volume control is off somewhere.... I know you have checked but could you double check that the audio for MP is not muted? I am sure you have done this already but each app has its own volume control in Win7 so you need to open MP in windowed mode (or press ALT+ENTER to get there) then just check the mixer option in Win7 volume control and be 100% sure that the slider is not off.