OpenROV 300: Going forwards means "switch off"



last night I finally finished my OpenROV. Tests of propulsion were fine at all. But in the bathtub I had some difficulties: Going up and down was ok - backwards, left and right as well. But moving forward just make a little jump an then I had no currency on my beaglebone any more.

I had to take it out of the water, dry it and remove the batteries. After that I could reproduce this failure.

Any ideas?