Advanced settings tab not displayed

The "Advanced settings" tab is not displayed in my Drupal 6.3 setup.
I knew about its existence because I use Drupal Administration Menu that shows it.
I think this is because a MENU_DEFAULT_LOCAL_TASK menu item is missing.
I have written a workaround but it may need revision.

  // add these lines in fast_gallery_menu() function
  $items['admin/settings/fast_gallery/fast_gallery'] = array (
    'title' => t('General'),
    'access arguments' => array (
      'access administration pages'
    ),
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -20,
  );