It's on the remote in the setup menu. Hold the Pronto icon - oh crap, your screen isn't responding is it. Duh, my bad. I guess trying to calibrate something that wouldn't respond wasn't such a hot idea either.

An alternate possibility is a loose connection inside the remote. Depends on how comfortable you are cracking the case. It takes a a #7 Torx screwdriver and there's another screw hidden under the lable on the back.

Jim L