EVS Web Knee Braces..what the?

Ok, so I just got one of my knee braces in, and I`m setting the stops on it. When I go to tighten the screw with the washer on it, the screw tightens up, but too soon. After it is "tight" the stop washer can still spin freely underneath it, which I think should be nice and snug..its like the screw wont go all the way in and just tightens up. I even tried screwing it in from the outside of the brace and same thing. It says in the directions, "use the small black screw", well only 2 silver ones came with the brace. Am I missing screws or am I just straight retarded? Thanks for any help..