Here is an interesting article in Velo News regarding Stuck Seat Posts. If you fail to do some maintainance of cleaning and loosening at least once a year, you might become stuck with this same problem which could be big. Every year at the end of the season I take mine out, clean it, and add a light coat of high quality grease to the post. I also put a fine bead of silicone where the post itself meets the seat tube. This will help prevent water from running down the post into the tube itself. Simple but, effective. I have never had a problem.