On December 30, 1998, at 1830 central standard time, a Cessna P210N, N731YY, piloted by a commercial pilot, received substantial damage on impact with terrain during landing on runway 04 (7,301 feet by 150 feet, concrete) at the Chippewa Regional Airport, Eau Claire, Wisconsin. The 14 CFR Part 91 business flight was operating on an instrument flight plan. Night visual meteorological conditions prevailed at the time of the accident. The pilot and three passengers reported no injuries. The flight originated from the Kalamazoo/Battle Creek International Airport, Kalamazoo, Michigan, at 1615, en route to Chippewa Regional Airport. In a written statement, the pilot reported, "The approach to landing went normal with the pre-landing checklist completed and all gauges indicating normal. On short final I rechecked to make sure the gear was down-and-locked by looking out the left window to check the position of the gear (it was down), and double checking that the "green light" was on, to indicate that the gear was locked (it was on). Touchdown was at 80 KIAS [knots indicated airspeed] and very smooth. I decided to keep the weight off the nose gear as long as possible, because of a shimmy in earlier flights, and the aircraft became airborne again, rising a few feet off the runway. I then added a little power to keep the aircraft from stalling and continued the flair. Suddenly the aircraft nosed down and the nose wheel gently bounced off the runway. I brought the nose back up and the plane then settled smoothly onto the runway. On rollout the plane wanted to pull to the left making me think that the left tire was flat. Around the last five feet of the roll out the aircraft slowly tilted to the left and came to a stop about 15 feet right of centerline and about half way down the runway. As the plane came to a rest, I thought that the left landing gear was collapsing, due to the tilt of the aircraft." During an interview, the pilot reported that he did not use a written checklist to perform the before landing checks. He also stated that the outside mirror (used to check the landing gear position) only shows the position of the nose landing gear. An aircraft mechanic at the airport reported that he found the nose wheel landing gear was in the down position with the main landing gear in their gear wells with the landing gear handle in the down position. The aircraft was placed on jacks and when the master switch was placed into the "ON" position, the red gear in transit light illuminated, the landing gear extended and the green gear down light illuminated. The gear was then cycled approximately six times and operated normally. The mechanic attributed the failure of the gear warning horn to a stiff cable which is to be replaced in accordance with a 1981 service letter which was never complied with.