[Merriweather]

This whole random inability to post is really troublesome on my forums. It's the same DB error over and over:

Database error in vBulletin 3.6.5:

Invalid SQL:

SELECT COUNT(*) AS replies
FROM grps_thread
WHERE threadid =;

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 3
Error Number : 1064
Date : Monday, March 5th 2007 @ 09:47:35 PM
Script : http://www.<edit>.com/groups/newreply.php
Referrer : http://www.<edit>.com/groups/newreply.php?do=newreply&t=98
IP Address : <edit>
Username : <edit>
Classname : vb_database

We can't find any rhyme or reason for it, but some of my groups, you can only start threads and can't reply to them at all!!!