Hi EndLess:
Welcome to my obsessive nightmare! I have tried all the thing you listed as well: press the reset button the back; check/uncheck the user defined hard key; download some other templates with the hope that my current template cause problem! No thing is seem to work. I'm very confidence now that the problem is firmware not hardware. I took a very close look at the remote but couldn't find a way to pry open the case; so I have not done that yet. Anyway, I'll give URC supporting team a call tomorrow to see if they have any idea. Will keep you update.
Good luck!
bt