This remind me of troubles i had while tinkering with overclock and undervoltage. If the chip is not powered properly, you can have this. Also, if you have kp installed, be sure to load the default profile, not the "dsp" one which increase dsp freq for 720 recording. If you did not tinker with kp and overclock, maybe this file need a special codec? did you try to install the extra decoder package after you flashed your beast?