MySQL Error Occured

Error Message:
1062: Duplicate entry '8ce9e577f278c8dfc6ec70fe8b3e5af0' for key 1

SQL:
INSERT INTO cube_CubeCart_sessions (`sessId`,`timeStart`,`timeLast`,`customer_id`,`ip`,`browser`) VALUES ('8ce9e577f278c8dfc6ec70fe8b3e5af0','1268291644','1268291644',0,'38.107.191.88','CCBot/1.0 (+http://www.commoncrawl.org/bot.html)');