I've been using RB almost daily for the past few weeks with no problems.

Suddenly today when I try to play a song it goes OK for about 15-18 measures... then the sound starts fluctuating 2 seconds on... 2 seconds off... 2 seconds on... 2 seconds off

once this happens, RB is locked up so tight that even task manager can't shut 'er down.

I've returned to factory settings multiple times. As I write this, the hard drive is defragging.

Any ideas?