I was setting up last weekend and the front scissor jacks won't stay in place. The front is lower than the back, so the jacks aren't deployed terribly far. Maybe 12-14 inches. I crack them down to stabilize, and as soon as I take off my drill, the screw spins backwards and the camper comes down. Mind you, I'm not trying to lift the whole corner, just bring the stabilizer down and put some weight on it. I didn't think these screw jacks were supposed to be able to do that. Any similar experiences?