perhaps the n9 isn't fully recharging its battery? I've noticed that when plugged in via usb to my computer, and the led turns green (theoretically fully charged), and then I unplug for a few minutes, mess around with it, and plug it back in, it seems to take a longer-than-expected time to turn green again (~10 minutes). You'd think it be pretty quick.

Don't know how everyone is recharging their unit, but try it with the provided power supply, not computer->usb. I recharge with the dumb power supply and haven't seen any power drain issues.

In pr1.1, I think they tweak some of the battery charging behavior, and maybe that has an issue of some sort.