Try holding the brake pedal down when you stop the car to park it. Before you put the car in park, set the parking brake while your foot is still on the main brake. Then put it in park and let you foot off the brake pedal. This should make it easier to get out of park. My Contour had the same problem you described, and it did it only when it was cold. The above procedure worked for my Contour just fine. This will also work if you park facing downhill.
