Fuel used

Hi to all. I am right now flying the World Rally 2008 and using the MAAM-SIM DC-3 with Mark's alternative panel. I am using the timer for my time and the digital fuel gauge for my fuel used. I do not know where my problem is but my fuel used is coming out as half of what it should be. The way I check it is clicking on fuel used and I thought that would give my total.I did flight 03 and 04 of the World Rally and these are the numbers:03 was 209 miles with heavy winds, it took me 110 minutes and the gauge read 94 gallons used.04 was 121 miles and some winds, it took me 55 minutes and the gauge read 46 gallons used.In both cases I tried to keep my speed close to 140 knots while cruising and the RPM stayed 2300 while climbing and 2100 during cruising. MAP around 30.I does look like is only giving me the fuel used by one engine, but I am flying with both.Can somebody help me with this problem?Thanks.Hector