Why does Netflix on Xbox 360 lock up the machine?

I keep having problems with Netflix on an Xbox 360 go to an all black screen and the Xbox stops responding until I cycle on/off on the Xbox (not the remote, it does nothing). This happens while watching a movie and pressing the on-screen stop, and on the on-screen skip back (especially near the movie beginning). I’ve had it happen (go all black and lock) at other times, too.