I have a nomadio in mine for a year and I haven't had any problems with it until recently. For some reason, I started getting the exact same problem as yours - very short range and it would go into failsafe - I did set mine to close the throttle and apply partial brake though so it would run away. I did notice that when it was sort of in range, it would glitch and start to become a run away before it finally lost all signal and go into failsafe.
What was the solution?? Don't know, but I did reload new software into the nomadio transmitter and recievers thinking that their proms had lost some of the software. I'm kind of thinking though that it might be related to either the coil of the engine or the loosening clutch springs since the clutch is dragging a bit even a slightly above idle since the same engine/clutch combo caused glitching problems in both of my vehicles.
