Do you have any other controllers plugged in? I had the same problem, I unplugged my usb flight joystick and gamepad and restarted FMS with PPJoy running Zhen Hua 5 byte protocol set channel order to 64356435 and and reversed the throttle switch on the transmitter and it works. I hope this helps
P.S. I am running Windows XP and FMS Alpha 8.5