I use SharpCap to get a good polar alignment before imaging. I tighten the altitude clamps a bit more before proceeding. I finish up, with good tracking results. The next evening, when I check polar alignment, the altitude is much too high. Releasing the altitude clamps causes the mount altitude to drop some, and get it is now close to proper alignment. What could be happening that causes this? Is there something I am not doing correctly with the altitude clamps?