I think that you have may have the post_table since that query can't delete it, just check the DB tables and look if is there. If you haven't phpMyAdmin access you can grab a tool for handle your DB externally (a php script).
Now I don't think that this is caused by a mod but can be a reason so, remember wich mods do you have installed, also add this line in the config.php to disable all the hooks:
Code:
define('DISABLE_HOOKS', 1);
Just simple tips that
can help you.