I been noticing an interesting phenomenon when trying to focus on things using any focus point other than the center focus point. Sometimes the camera just can't seem to 'lock on' the subject as easily and quickly (or sometimes not at all) when using either top, bottom, right or left focus points. Move the focus point to the middle, and it locks on quickly and accurately. Has anyone else noticed this? Do other Nikon cameras do this? Does the D300 do this??? Should I upgrade ! ????