Duplicate entry '*****' for key 2

Time: 2010-01-28 03:00:20
Server: programmer.lt
IP: 79.98.25.186
User agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.8.0.1) Gecko/20060111 Firefox/1.5.0.1
Error:
MySql query: INSERT INTO p_servers(server_id, server_ip, server_name, country, continent_code, country_code, country_code2, region, city, postal_code, koord1, koord2, dma_code, area_code, updated) VALUES(NULL, '212.61.252.88', 'srv252088.webreus.nl', 'Netherlands', 'EU', 'NL', 'NLD', '06', 'Eindhoven', '', '51.450000762939', '5.4667000770569', '0', '0', NOW())
MySql error no: 1062
MySql error: Duplicate entry '212.61.252.88' for key 2

CREATE TABLE IF NOT EXISTS `p_servers` (
  `server_id` bigint(20) NOT NULL auto_increment,
  `server_ip` varchar(100) NOT NULL,
  `server_name` varchar(255) NOT NULL,
  `continent_code` varchar(50) NOT NULL,
  `country` varchar(255) NOT NULL,
  `country_code` varchar(10) NOT NULL,
  `country_code2` varchar(20) NOT NULL,
  `region` varchar(50) NOT NULL,
  `city` varchar(255) NOT NULL,
  `postal_code` int(11) NOT NULL,
  `koord1` varchar(100) NOT NULL,
  `koord2` varchar(100) NOT NULL,
  `dma_code` varchar(50) NOT NULL,
  `area_code` varchar(50) NOT NULL,
  `updated` datetime NOT NULL,
  PRIMARY KEY  (`server_id`),
  UNIQUE KEY `server_ip` (`server_ip`)
) ENGINE=MyISAM  DEFAULT CHARSET=utf8 AUTO_INCREMENT=72680 ;