Duo-Therm Controller Problem

[D2]

In November 2005 we had the Duo-Therm controller replaced in our 2000 Newmar Mountainaire.  It has been working fine until this morning.  There was a period of time that it would only give me the choices of "Off" or "Furnace".  After some time and pushing of buttons, it finally gave me the other choices of "Heat Pump", "A/C" and "Fan Only".

Any ideas of what would cause this?

Thanks!!