K770 has 3.15MP cam with LED flash and K800 has 3.2MP cam with xenon flash.
If you flash k800i to k770i you have phone with working flash menu and not working: keypad, joystick, camera and radio.

K800 in the K770i
Pluses: redesign, TrackID ™, support for Flash Lite
Negative: The camera does not store photos. Joystick becomes very sensitive.

Nice day