If you will fold the stock, you should see an allen headed bolt on the lower left. This is the stock tension adjustment and backing it out a little will take out the wobble. A little movement goes a long way.
There are two adjustable screws. There is the gap adjust screw, which I believe is the one Jeremy is talking about. The one that adjusts the stiffness of the folding action is the long allen bolt that goes through the hinge itself. If you tighten that, you will be able to fold the stock and have it stay. There should be something in your manual illustrating this.
I went through my XCR a few days after i got it and made sure everything was tight. I couldn't figure out why, the next time i went to the range, the stock felt so loose. I finally figured it out while at the range but for a few moments I really was completely stupified.