If you sew over a pin with a computerized machine it will screw up the adjustments of the computer. My machine repair shop states that after a computerized machine is adjusted, set it up and leave it. Every time you move it, it will shift some of the computer adjustments. When I want to sew over a pin, I stitch just up to the pin and use the handwheel to jump over it. If the needle will hit it, you can make adjustments before it dulls the needle or worse.