Well I'm an idiot - the fulltext index on page_text was missing from a default installation. It didn't break searches but probably slowed them down tremendously. Also set engine to MyISAM on page_text to avoid cryptic error messages from MySQL.
<?php
/*
* Admin theme for Enano
* Created by dandaman32 - (C) 2007
* License: GPL
*
* This theme is free software; you can redistribute and/or modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
*
* This theme is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for details.
*/
global $theme;
$theme['theme_id'] = 'admin';
$theme['theme_name'] = 'Admin';
?>