I my Centery and Unlimited radios are PPM and I had set my 388s to ppm. AFPD works great just as long as I don't load a jet (of any kind) and a helicopter (of any kind). If I do AFPD starts missing up and my trans shows up as a 3 channel and the controls (red bars) start flashing back and forth. I'll try the grounding thing to see if that helps.