SQL-DATABASE ERROR

Database error in WoltLab Burning Board (2.3.6): Invalid SQL: INSERT INTO bb1_sessions (sessionhash,userid,ipaddress,useragent,lastactivity,request_uri,styleid,langid,authentificationcode) VALUES ('2b0b69a6ce4733d3cc5190e1fb1ce2de','0','38.107.179.223','CCBot/1.0 (+http://www.commoncrawl.org/bot.html)','1337336350','download.detail16.296.html','0','0','')
mysql error: Duplicate entry '2b0b69a6ce4733d3cc5190e1fb1ce2de' for key 'PRIMARY'
mysql error number: 1062
mysql version: 5.1.47
php version: 5.3.10
Date: 18.05.2012 @ 12:19
Script: /download.detail16.296.html
Referer: