the first incoming links admincp

[abbasbsp]

beginning of VB4 Downgrade into vb3, all right
but at the first incoming links admincp, there is always a database error

Database error in vBulletin 4.0.2:

Invalid SQL:

SELECT COUNT(*) AS count
FROM attachment AS attachment
INNER JOIN post AS post USING (postid)
WHERE attachment.visible = 0;

MySQL Error : Unknown column 'postid' in 'from clause'
Error Number : 1054
Request Date : Sunday, February 28th 2010 @ 07:39:22 AM
Error Date : Sunday, February 28th 2010 @ 07:39:22 AM
Script : http://mydomain/admincp/index.php?do=home
Referrer : http://mydomain/admincp/index.php
IP Address :
Username : bigger
Classname : vB_Database
MySQL Version : 5.0.89-community

Please help me