Spoonman, Is it due to shrinkage in the cold? Or does the zipper simply need some lubricant? If it's due to being too tight because it has shrunk when it dries, try taking the pressure off by relaxing the tension on your poles or guide wires (tie downs). If it's due to the zipper needing lubricant, some guys use chapstick on them. Otherwise I think they sell stuff for that problem where they sell camping supplies. Your other option, probably most expensive, would be to take it to a place that makes boat covers and have the zipper replaced. Good luck with it. I know it can be a real pain particularly when the fingers aren't as nimble in the cold or arthritis issues exist. Lou