Does X chocks help stablity?

I will say that one of the first times i used them one actually fell out in my hand several hours after placing it. I assume, and believe that the tires had cooled sufficiently to allow the chock to loosen. I now re check them after application. Lantley, your point about using additional chocks on slopes is a good one, and I would hope that any users would do so in that circumstance. Just as with most things, these are subject to operator error. Happy trails!