Well, I've now got my NCE Pro Cab radio controller back from repair. It works fine now. However, I was about to send it back AGAIN for the problem of it not responding, the LCD display not updating, and appearing not to reposnd, and having to push the buttons a number of times.
However, it was my problem. I was using it too close to the radio base station. Move more than about 2 - 3 feet away from it, and it works, and responds fine, with the LCD display updating when it should. Move close to the radio base station, and it plays up, as joepomp and I both described. I have not yet tested how far away from the base station it will work, however Garahbara takes up a double car garage, and I've had no probs with it responding correctly, first time, every time no matter where I am around the layout. Except, of course, if I'm within 2 - 3 feet of the radio base station.