I am trying to learn the P,S,A and M modes. I am doing well with all except Mode P. I have been thru the manual, this web site and other web sites. Per online manual I can set Mode Dial to P, and then I can use the Command Dial to chose a combination of aperture and shutter speed. When I move the command dial, left and right nothing happens. I do get the P* in the display and I can use multi-selector to change other settings (like ISO or AF). However moving the command dial does not change the aperture and shutter speed even after I do a half click on shutter to get a meter reading. Any advice would be appreciated.