I picked up a used pistol grip head yesterday, but once I mounted it, I realized that the camera base plate is wobbly when mounted to the head. As I'm not a big tripod user, I have to ask... I expected the base plate should fit snug, so the camera doesn't wobble, not even by a mm. So that adjusting things like focus and aperture between shots won't move the camera. No? I'm planing to return / exchange it for a different head today, but I wanted to make sure before making that trip.