I have the same problem with the power cutting out after flying for a little while. I was going to post about it, and then discovered this thread.

So.... I copied and pasted the "electric_always_available=1", it seems to have made no difference. Did two flights in the last two days and the power cut out both times shortly after take-off. Does this fix work for everybody? Only after running the APU did I have power on again. Basically I have to run the APU all the time if I want to use my GPS (which I do).

Also shouldn't the fuel load change after running the APU for a length of time on the ground? Thanks.