When the ardupilot has the ArduCopter 2.0.56 firmware (I believe this is the most current) the servo output on all channels is zero, the servos jitter and thrash and the BEC becomes very hot.
http://youtu.be/8ku2r5M-hZg
When the arduplane firmware is loaded, everything is 'smooth' like I would expect. This autopilot has done 14 flights as an arduplane, zero crashes. Everything is working fine…