Today i installed 2.37 on my quadcopter. First impression WOW!!! Alt holt is impressing..   But after some flying the quadcopter suddenly turn(yaw) 90 deg (in simple mode) and i was not able to steer because he was now and then turning 90 deg, always counter clockwise... Made a quick landing without broken parts...that was the good part..a few months ago i lost a quadcopter..   i have no compass.…