Attributing a particular IP address to a specific location is hard and often fails miserably. There are several difficulties that I have talked about before: Out-of-date whois data, data that is outright fake, or was never correct in the first place. Companies that have been allocated a larger address range are splitting it up into different geographic regions, but do not reflect this in their whois records.
Article Link: Whois "geofeed" Data - SANS Internet Storm Center