If I am in spot focus mode, and want to move the focus to the side of the frame, I just make sure the focus dial is unlocked, then move the dot to where I want to focus, then take the picture. Works fine, but after the shot I generally want the focus back in the center, so as to be ready for an unpredictable shot. The problem is that the focus dot will not move back to center, unless I shut off and restart the camera. Anyone know why?