I've only ever had the power problem once. I started a Topic on it, but it has never happened again. I did some testing, that took a day (18 hours) to do, but the APU started every time I tried it and I never lost the power to the aircraft over that 18 hours. The engines and APU were OFF for most of that time. I would wait about 2 hours before starting the APU, then start the engines. After the engines were started, I turned the APU OFF, the shut down the engines.

So like RobWilk, I've done hours of flights in the 737, and of all the Captain Sim aircraft, it's my favourite.

Yes, there ARE fixes need for the 737, but the ones that bother me the most are the following:
(1) The engines are far too powerful for the aircraft. The change I made, static_thrust = 16000 helps, but I don't really know what it should be.
(2) The PDCS occasionally causes FSX to crash, but if I enter the data very carefully (slow and deliberate clicks of the keys) it doesn't.
(3) The PDCS isn't tied in to the EPR Reference Bugs, so you have to set them manually. I'm not sure if the engines are NOT supposed to exceed the EPR setting, but they do anyway.
(4) The FDE doesn't seem to be realistic. I don't know if they aren't, but going by what many others say, it isn't very realist.

As for any others, I don't feel they are as important as the ones I listed, but it would be nice for them to be fixed too.