I have the wide angle and telephoto accessory lens for my G9, along with the LA-DC58H adpater. Aligning the white bar on the adapter with red dot on the camera body I wiggled the adapter until it fit on the body, then turned it clockwise. Now I want to remove it, but the release button is completely depressed and the adapter rotates a few degrees back and forth. I don't know how I did this since I followed the instructions in the Canon knowledge base for attaching the adapter. Advice needed.
Fixed it. Gentle twisting and pulling released the lens adapter. The Canon instructions are wrong. Their "Procedure For Using Addon Lenses -- PowerShot G9" says to attach the LA-DC58H, align the small white bar with the release button and turn clockwise. Nope. Futzing with the ring I discovered that after aligning the dot with the release button I had to rotate the ring counter-clockwise until it fit against the body, then turn it clockwise until it stopped. Released the ring, aligned the adapter white line with the release button and turned conter-clockwise until it settled fully against the camera body. Then I turned it clockwise until it stopped. Easy to remove by pressing the release button and turning counter-clockwise again. Whew!