I have had 3 of these now with bad results. (All AR636A receivers). The last one will not bind to my DX8 although "regular" receivers bind with ease. The previous one: while flying straight and level the plane suddenly did a forward flip and spiraled into the ground with no control. Both batteries had full charges and have been normal since. All Spektrum product people can say is " I don't know. Send us the receiver and we'll see" Anybody else have this problem or any knowledge of it?