I have the same <problem> like pragnanzer, the display backlight isn't automatically switched off while charging when the device is powered off. Nokia careline told me the same like you said, that it sould be turned off automatically after a few seconds, but it doesn't. Sliding the cover over the device, Nokia said, will turn the display off, like others in this thread experienced. I will also try this.

My question:
Did anyone really see that the Nokia 770 turns the backlight off automatically while charging in powered off mode (so that my and pragnanzer's device is not working properly)?