Duplicate entry 'xxx' for key 1 in userfield
 

Database error in vBulletin 3.8.3:

Invalid SQL:
INSERT INTO userfield
(field5, field6, userid)
VALUES
('Jordan', 'male', 99355);

MySQL Error : Duplicate entry '99355' for key 1
Error Number : 1062
Request Date : Sunday, July 26th 2009 @ 05:57:27 AM
Error Date : Sunday, July 26th 2009 @ 05:57:27 AM
Script : xxx/register.php?do=addmember
Referrer : xxx/register.php?do=register


and I see some topics talk about this problem here and here

and my Records
user 84,267
userfield 98,416
usertextfield 98,416


how to fix this problem