[D.Ilyin]

but.....

Database error in vBulletin 3.5.4:

Invalid SQL:

SELECT thread.forumid, firstpostid, postid, parentid, thread.threadid
FROM vb_post
INNER JOIN vb_thread as thread ON (thread.threadid=post.threadid)
WHERE post.postid IN (2);

MySQL Error : Unknown table 'post' in where clause
Error Number : 1109
Date : Thursday, June 1st 2006 @ 05:53:37 PM
Script : http://localhost/vb0/inlinemod.php
Referrer : http://localhost/vb0/inlinemod.php
IP Address : 127.0.0.1
Username : admin
Classname : vb_database

ONLY when try to change owner from inside thread .

UPDATED
And as a future suggestion:
decrease amount of posts old owner and adding amout to new owner of the thread.