Daniel - Yes, I eventually was able to get one other code to learn from the MX700. But just one of many that I have tried and would like. And this was after many attempts: (long hold, short hold, after erasing learned code, after erasing entire device, before naming the button, after naming button, after update to firmware...) well that is just about all the options I can control and I am now giving up on the fickle MX450. And the screen is shot - no longer gives me the "next" and "back" messages on the bottom in program mode and there ore other visual errors on the screen which only foretell more problems. (after 3 days use).
The Harmony One? yeah, learned them all no prob. But I hate the touch screen and my kids hated the delay so they never used it. And that is the death knell of any Harmony product because then everything is out of whack all the time. If only URC and Harmony could join forces and build a usable friendly remote. So I guess I will stick with the 10 y/o remote. Do you know where a guy can find a slightly used/new MX700?