OK so i just purchased a used 17mm lens off this forum, I received it yesterday and was so excited that I immediately put it on my camera (A Panasonic G1) and went out around town to take pictures with it. I absolutely loved the look of this silver lens against my Black camera and its field of view, However I noticed that it would refocus even when i did not have my finger on the shutter release button. I thought it might have been my eyes so I took it away from my eye, made sure it was set to AF-S and looked at the lens on the camera and moved the camera around. Sure enough when pointed to something very close, i seen it refocus , then pointed to the sky, i seen it refocus again. It was not a clicking sound or anything, i could actual see the front of the lens moving in and out. I know that's focusing . Now it was not moving as fast or as often as it does focuses when I press the shutter button but it does refocus when I'm not touching any buttons and when set to ether AF-S or AF-C. It only stops when set to MF. I have never heard of any problems with this lens on a Panasonic Body. Does anyone else experience this? Is this something that is normal for the lens or did i buy a faulty copy? I have a M.Zuiko 14-42mm II lens that i use as ,y standard Zoom with no issues.