What Port do you use for the bluetooth module? Main or Flexi? Can you try the other one?
Edit: I just pushed a fix to alpha, that will prevent the crash, but might not immediately stop the issue. If you are experiencing a lot of bad packets, and no good packets, please try to reconfigure Flexiport/Mainport to another speed and back, and/or change the port. This fixed the issue for me.
-- Marc