unregister_hook('plugin_settings', 'addon/pageheader/pageheader.php', 'pageheader_addon_settings');
unregister_hook('plugin_settings_post', 'addon/pageheader/pageheader.php', 'pageheader_addon_settings_post');
unregister_hook('plugin_settings', 'addon/pageheader/pageheader.php', 'pageheader_addon_settings');
unregister_hook('plugin_settings_post', 'addon/pageheader/pageheader.php', 'pageheader_addon_settings_post');