have you tried to stop the music and play again? And maybe wait for 10 seconds just to be sure the sound is not back.
And since you have the build tablet. Can you verify if video plays properly in Metro (try the Win7 sample video)? Like, is there a blank screen with sound when you first started playing the video? And how smooth is the Solitair game? just want to see if my HW is incompatible or not.