Hi mec:

The gear switch up detection when powering up the transmitter was added this year. If the receiver put out an erroneous pulse during power up, this could of detected it.

Do you use a 6 cell battery? If so, and you have a fresh charge, it can cause the sequencer to glitch. Even if you have a regulator! I put a diode in series with the power lead to drop the supply voltage by about a 1/2 volt to the sequencer and valves if I use a 6 cell pack. A 1N4000 or equivalent diode works fine.