OK, I just bought a used P20, and I noticed something peculiar. The lens keeps focusing when I move the camera around without me pressing the shutter button. Also, the choices I am given for AF are only AFS and Manual (no AFF and AFC). When I put it on Manual then it focuses with the focus ring, but on AFS it focuses with the shutter button half-press as well as on its own when I move the camera. Is this normal? By the way, I use it on a GX1.