I sort of have the same problem...
My camera surprisingly slipped off my tripod, and fell on a hard solid floor. My camera was on at that time (lens were out and ready to snap a picture). Whenever I try to start up the camera, the lens start to twitch in and out about 1mm. The lens won't go back in the camera. Also, the lens won't even come out any further. So, therefore, the lens is just stuck right in the middle doing nothing but twitching, after starting up the camera.
Because of this, my camera keeps notifying me to turn off the camera and turn it back on. There's no use. The lens seems to be dent.
People also say that it's really hard to fix the lens.
Anji
March 2007