I have been wondering about the flight history issue as well. I was hoping there was a way to save and review past flights. I like the fact it shows your flight track while in the air, but would like to be able to review it on the ground.
I have had no issues with the flight timer, myself. It seems to work consistently. However, being busy in the pattern, I don't look at the flight duration until I'm on the taxiway, and by then it has gone to zero.
Gary