Make sure that the camera name in the parameters pallet matches the camera name in the document (scene) window.

Even then the focus prop (to give it its full name the "FocusDistanceControl" prop), only shows whilst you are actually using the focus_Distance dial. At least that's how it works for me in P6. It's possible to make a pose file that would force the FocusDistanceControl prop to display all the time, but I'm not sure that is a good idea.