I am having trouble figuring out how to use my Canon C100 with the Manfrotto MVH500A Fluid Drag Video Head with MVT502AM Tripod. The plate comes with one giant screw but that only holds the plate to the front of the camera, When I put it on the tripod the back of my camera is lose and can slide around. How do I solve this problem? I was on the B&H questions and answers section and asked about this and they mentioned the black pin that should keep it in place, I did put the black pin in but since it is in the front which is where the big screw is, that leaves the back of my camera still able to swivel. Pleas help, thanks!