Help: MySQL error after making some changes....

[GTX2]

i don't know what's happening, but after replacing some user profile fields, i start receiving thousands and thousands of vbulletin database errors in my email, with this content:

Database error in vBulletin 3.6.4:

Invalid SQL:

SELECT user.usergroupid, userfield.field28
FROM vbbuser AS user, vbbuserfield AS userfield
WHERE user.userid = ' 15610 '
AND userfield.userid = ' 15610 ';

MySQL Error : Unknown column 'userfield.field28' in 'field list'
Error Number : 1054
Date : Sunday, April 13th 2008 @ 12:37:39 PM
Script : http://www.myurl.com/showthread.php?t=48012
Referrer :
IP Address : xx.xxx.65.235
Username : Not registered
Classname : vB_Database

Can someone help me out?
Browsing the forums i got no errors, but i receive thousands of this email errors!

thanks