[Marco van Herwaarden]

To troubleshoot this, please remove any hacks and disable your plugins, then see if you still have this problem.
Note: To temporarily disable the plugin system, edit config.php and add this line right under <?php

define('DISABLE_HOOKS', true);

If so, reupload all the original vB non-image files (except install.php). Make sure you upload these in ASCII format and overwrite the ones on the server.

If this still does not solve your problem, then it is a mistery to me why this table is gone both from your database and your backup. Is the backup made using the same vBulletin version as you have installed now? Also as asked before, did you do any recent maintenance or such?