Where to include a new variable?

[Defkalion]

Ok I'm coming back on this, since I solved it - but partially;

I have created a plugin with this code;

PHP Code:

$stories = $this->registry->db->query_first("
                    SELECT count(threadid) AS num
                    FROM vbthread AS thread
                    WHERE 
                       ( forumid = 57 or
                        forumid = 58 or
                        forumid = 59 or
                        forumid = 60 or
                        forumid = 61 or
                        forumid = 62 or
                        forumid = 63 ) and
                        postuserid = " . $post['userid'] . "
"); 


And then I use the variable $stories[num] inside my postbit template to display the result. This part is working fine.

But now I cannot use my external RSS forum feeds, I get a database error, saying that:

PHP Code:

Database error in vBulletin 3.6.8:

Invalid SQL:

                    SELECT count(threadid) AS num
                    FROM vbthread AS thread
                    WHERE
                       ( forumid = 57 or
                        forumid = 58 or
                        forumid = 59 or
                        forumid = 60 or
                        forumid = 61 or
                        forumid = 62 or
                        forumid = 63 ) and
                        postuserid =;

MySQL Error  : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 11
Error Number : 1064
Date         : Wednesday, January 9th 2008 @ 12:29:11 PM
Script       : http://www.MYDOMAIN.COM/external.php??type=rss2&forumid=57
Referrer     :
IP Address   : xxxx
Username     : not registered user
Classname    : vb_database 


I think this is because of the HOOK location I've put my plugin in. I put it in postbit_display_start. Is this correct? Should I choose another hook location?