On February 11, 2006, about 1418 eastern standard time, a Cessna P210N, N6504P, registered to and operated by a private individual, experienced collapse of the nose landing gear during the landing roll at the Sarasota/Bradenton International Airport, Sarasota, Florida. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 CFR Part 91 personal flight from Okeechobee County Airport, Okeechobee, Florida, to Sarasota/Bradenton International Airport. The airplane was substantially damaged and the commercial-rated pilot, the sole occupant, was not injured. The flight originated about 1330, from Okeechobee County Airport. The pilot stated that after takeoff the flight proceeded to the destination airport where he was cleared to land on runway 14. He reported he lowered the landing gear and confirmed he had a green landing gear extended light and he visually saw that the nose and left main landing gears were down. He turned onto final approach and reported the landing was "...firm but not a hard landing." As the nose lowered he heard the propeller contact the runway and the airplane slid to a stop. Postaccident examination of the airplane was performed by an FAA airworthiness inspector following recovery. The airplane was placed on jacks, and gear retraction and extension tests were performed. No discrepancies were noted with the retraction and rigging tests. The "down switches and warning horn operated normally." Disassembly of the nose gear down lock mechanism revealed no discrepancies. The hydraulic reservoir was full, and there was no hydraulic fluid leakage or nose landing gear structural failure. Slight movement between the 2 down lock hooks was noted, but no locking or binding was noted. The electrical strip at the top of the nose landing gear was noted to be oily and dirty where the nose landing gear down switch wires were connected, and a protective rubber cover contained a small amount of oil and dirt.