A possible scenario: The battery runs dead, and the user tries to reboot with the dead battery. The weakened battery either doesn't turn on the screen and he/she turns the unit off, or the 770 dies during bootup. Either way, the bootup cycle is interrupted, which could be corrupting the video drivers, the USB drivers, and who knows what else.

This is just a guess... but for Windows users, it can be a very bad thing to power off during bootup. If this is the case with the 770, Nokia needs to detect and protect the unit when this happens, or at the very least allow system critical drivers to be reinstalled in the event they become corrupt.

Just to be safe, though - if the battery runs down, plug it in before you try and reboot.