iPhone screen stays on too long
Can anyone tell me why my screen would stay on longer than a minute when the phone isn't being used? Sometimes I've noticed this when it's attached to a music dock or via USB to my laptop, but lately it seems to stay on even when it's sitting on my desk unconnected to anything. Easy enough to shut off the screen by pushing the button on top, but I'm using up battery power I don't want to, and it seems like the phone should go to sleep sooner than it is.
iPhone 4, iOS 5.0.1