Problem Whit Registration

[محروم.كوم]

Hi , i have used impex for import one old database , now who try to register display an error


DATABASE ERROR

and receve one email

Code:
Database error in vBulletin 3.8.5:

Invalid SQL:
INSERT INTO userfield
(userid)
VALUES
(1246);

MySQL Error : Duplicate entry '1246' for key 1
Error Number : 1062
Request Date : Thursday, June 3rd 2010 @ 01:16:12 PM
Error Date : Thursday, June 3rd 2010 @ 01:16:12 PM
Script : http://www.wmaster.it/forum/register.php?do=addmember
Referrer : http://www.wmaster.it/forum/register.php?do=register
IP Address : 79.27.51.1
Username : NOMEOFUSER
Classname : vB_Database
MySQL Version :
Help me..! __DEFINE_LIKE_SHARE__