Facing error 1062

[neeshu]

I have imported a phpbb forum to vbulletin but it seems that whenever a user makes a post I face this error

Database error in vBulletin 3.8.2:

Invalid SQL:

                               INSERT INTO postlog
                               (postid, useragent, ip, dateline)
                               VALUES
                               (425, 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.10) Gecko/2009042316 Firefox/3.0.10 GTB5', 1975849442, 1243959371);

MySQL Error   : Duplicate entry '425' for key 1
Error Number  : 1062
Request Date  : Tuesday, June 2nd 2009 @ 09:16:11 AM
Error Date    : Tuesday, June 2nd 2009 @ 09:16:17 AM
Script        : http://www.exambazar.com/newthread.php?do=postthread&f=63
Referrer      : http://www.exambazar.com/newthread.php?do=newthread&f=63
IP Address    : 117.197.17.226
Username      : admin30
Classname     : vB_Database
MySQL Version :

I have set post to moderation so each post is moderated before being posted