I am sorry to say this, but you definitely are supposed to drive with the
propane on. 

Mine blew out while driving and I took it back twice to have it repaired
cause it went out while driving and Dometic paid the bill. They admitted that
the fridge is supposed to stay lit while driving and they make the fridge.

I cannot imagine anything more stupid than using the 12 volt system every
time you turn the key and then having to keep relighting the fridge every
time you stop. What a waste of time.

Typically, the reason the fridge blows out while driving is that there is an
air leak in the system somewhere. Typically, this would be that 1) the drain
tube has been left unplugged, 2) that the cumbustion chamber seal has a leak,
or 3) that the exhaust/intake hoses in the back of the fridge are of unequal
length. The unequal length in the tubes allows it to get drafty and this
blows out the flame. 

The fridge should *never* blow out while driving. It only goes out if you are
forgetful enough to drive through the car wash with the fridge on the
propane, as I have sometimes done.

derekdrew@aol.com