After SP1 the fuel remaining is still showing incorrectly it still shows 120 gallons and is not dropping when the fuel level drops in the tanks

No help at all but I've not experienced this - all working tickety-boo  :wink:

I think the Navajo will be my final purchase from them 

Mine is the same. Stays at 120 throughout the entire flight. If I save the flight and carry on at a later time, it will adjust the amount of fuel to the correct level. Once again though it stays at that level and won't reduce as I carry on the flight.

I think Carenado needs to release another service pack for it

Well, I sent them a list of items that need fixing, and their reply, in so many words was, we may do another service pack, but if and when, who knows. I've sent them several things in the past, and it seems to be the same old song and dance. They seem to be quite busy updating Xplane stuff, but I guess updates for FSX has gone by the wayside. Guess they forget about customer satisfaction. Sort of like buying a car. It's yours, good luck.

Yep that's true