Thought I'd quickly share my own solution to a problem I've had. Using FMS and smart propo, I could never get the Tx to calibrate. The bars would jump all over the place. Using sound recorder, I could see a definite signal, but the amplitude was way too big.
Then, my surprise, after fiddling with the audio jack on the Tx side, hey presto! I found that turning the jack in the socket, the signal normalized and now FMS works. Weird!!