More info, I played with this transmitter a bit more. On the rudder channel only, I can program two rates for the dual rate and I can program exponential on all 3 prime channels. I can program the PMix okay to put one aileron on Channel 7 with the other on Chanel 1. Now, I have an FP-T7UAF also and it programs correctly. The FP-T7UAP instructions are the same so I'm now sure I am not causing the fault. The problem seems to be associated with the three dual rate switches (rudder, elevator and aileron) Any advice would be appreciated.