How might I fix this?

when trying to email an activation code via User Control Panel to a user I get this:

Database error in vBulletin 2.3.0:

Invalid SQL: SELECT user.userid,usergroupid,username,email,password,ac tivationid,dateline FROM user LEFT JOIN useractivation ON (user.userid=useractivation.userid AND type=0) WHERE email='chris@idp.net'
mysql error: Column: 'usergroupid' in field list is ambiguous

mysql error number: 1052

Date: Wednesday 04th of June 2003 07:05:00 PM
Script: http://groove-salad.com/forum/forum/register.php
Referer: http://www.groove-salad.com/forum/ad...it&userid=2057

[Xenon]

seems you made an upgrade mistake.

rerun the upgradscript of vb230 and reupload an unhacked register.php