> The reason for the control-b problem - will probably never be
> known, but
> the people who guessed that the cpu key might not be in the right
> position are probably close - in my guess.

There is one more possibility that we "discovered" while moving
to our new R&D offices:

Certain models have a little switch on the back labeled "normal" and
"service". This switch must be in the "service" position for CTRL B
to work. While we were moving, it got nudged into the "normal"
position and we too couldn't get CTRL B to work at any time.