I made a video of the snap up and the spring bar on one side. It's pretty boring, but it does show that's there's some motion in the snap up. It was surprising to me how often the little keeper pin is holding some amount of weight. I assume that when "popped out" the keeper is bearing a non-trivial (or certainly non-zero!) load.
http://www.youtube.com/watch?v=hg8XwpmSy_wI'm not sure if this help at all with the Dual Cam issue. I guess it does if whatever force is causing the arm to want to go "out" still exists with the Dual Cam setup.