I've had a bit of an odd problem that I think is related to Context loss.
I have handleLostContext set to true, and on some Android phones, if you lock the phone whilst my game is running it would fail to come back - you would get this weird black screen. I would also sometimes get the wrong orientation, and lost full screen.
As a test, I turned off handleLostContext, and then I started to see the critial error message the context was lost.
It looks like an Air problem, but it also looks like starling was failing to resume from the context lose?
Finally, and this is just weird, but the black screen for some reason would have one bitmap data displayed - the progress bar that I have on my preloader. I have no idea what it is doing there because it is destroyed and disposed after the app is initially loaded... so... yeah.