The Rain-Bird remote had many short commings, so your not alone. Most of their problems were with range and battery drain. This is one of the reasons RB quit making the rm-1 and the rmx-1 (plus they weren't big sellers either). I do know that they are in development of a newer version with much easier interface and programmability. I would look for the new version to be out mid to late spring 2007. Don't worry it should be backwards compatible with all previous controllers with remote ready. Give me a few days to research your problem and I will post my findings.
Josh
Irrigation /Landscape Lighting / Pump and Well Specialist