When you are making adjustment to a scope the crosshairs will move in the reverse direction you are dialing the adjustments. Such as when you move the dial up and the crosshairs move down. This is how they are supposed to work. You did the right thing by contacting Leupold. Shimming the base will correct the problem you have. This is needed more often than most people think. Good luck and your scope choice was a good one. I have had a Leupold Vari-X III 3.5-10X50AO for over ten years. In that time I have had no change of zero.