Trying to set default in navigation

[betterthanyours]

Database error in vBulletin 4.2.0:

Invalid SQL:

            UPDATE navigation
            SET state = (state | 2) & ~8
            
            WHERE navid =;

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 4
Error Number  : 1064
Request Date  : Saturday, October 13th 2012 @ 08:43:12 PM
Error Date    : Saturday, October 13th 2012 @ 08:43:12 PM
Script        : http://www.unrealkillers.com/admincp/navigation.php?do=dodefault
Referrer      : http://www.unrealkillers.com/admincp/navigation.php?do=default&navid=34
IP Address    : 81.109.188.17
Username      : SAM
Classname     : vB_Database
MySQL Version : 5.5.24-0ubuntu0.12.04.1

I tried

UPDATE navigation SET state = 2 WHERE name = 'vbtab_forum'

Is there an SQL command I could execute?