Just to confirm, is that pin the same pin on the Mega2560? Or is there a place I can check which pin is what online?
I wouldn't count on it. As far as I can tell from the hodgepodge that they call a 'Schematic' diagram it is Pin 10.
By the way you should be able to turn the square wave off with
TCCR2B = B00000000;
and back on again with another
TCCR2B = B00000001;
.
Don
Edit: It looks like it is indeed digital pin 10 according to: http://arduino.cc/en/Hacking/PinMapping2560