Why does my Canon PowerShot G1/G2/Pro 90 IS not work with gphoto2 when using the AC adapter?
This is a longstanding bug with the G1 and Pro 90 IS, and a relatively new bug with the G2. With the G2, it was introduced with a new camera firmware (G2 1.0.0.0 worked, 1.1.0.0 does not). We haven’t fixed this bug yet since none of the active gphoto2 developers owned one of these cameras until recently (i.e. updated his G2’s firmware).