Here's an update on our Dometic cooling problems:  

Just prior to our trip out west (the month of July), I was complaining on
the list that the fridge in our new 90 Westy wasn't cooling adequately on
110v, 12v or (expecially) gas.    On level floor.   In the garage.   Cool
(65F) outside temperatures.    Left it on for two days on 110V, then 2 days
on gas, and didn't get below 50F inside.   Plenty of roaring sound from the
gas burner, etc.   

Well during the 50-odd hours of driving from Boston to Montana, the fridge
somehow fixed itself, and was cooling semi-adequately (35-45F) for the rest
of the trip.

When I had discussed the symptoms with a Dometic expert before our trip, he
concluded that the fridge has formed crystals inside (apparently happens
due to overheating sometimes when run off level for long periods (by PO of
course)) and would need to be recharged (was not clear whether anyone still
can do this for our Dometic model or not).   

I conclude that the driving motion, and expecially the 200-300 miles on
dirt roads during the trip, somehow broke up the crystals.    May be
temporary, but it's still as semi-adequate as it was on the trip.   

SO - if anyone else has similar symptoms, try a bumpy dirt road before
giving up!    You may still need to have the system recharged eventually,
but might extend the useful life before springing for that.

Dave