What kind of remote are you using to control the ir543? I have an All In One Kameleon, and I had to program other buttons to use 11-16. It's because with the ir543, you can't hit 1-1 to get 11. You have to send an 11 from your remote, and since there isn't an 11 button, you'll probably have to program buttons for each number (11,12,13,14,15,16).
Kevin