I was having the same problem with mine learning the magnavox starsight comand "right" and "exit".
What I ended up doing was deleting all the button fuctions on that page and then went back to use mode and removed the batteries "rebooted" with reset and releaned all the buttons again. I figure that maybe all you have to do is delete that one and "reboot" and then teach it again. Mine works fine now but make sure the batteries in the source remote are good and that when learning the pronto is sheiled from interferance like forecent light ect. Good luck and enjoy I hope?