Search page form AJAX/AHAH does not work

In D6 it's AHAH; in D7 it's AJAX. And in between there have been changes to how it works.

It looks like there's supposed to be a name and path suggested when you change the search type on the search page form, but the AJAX has not yet been adapted to work with D6.

 $form['info']['search_type'] = array(
    '#title' => t('Search Type'),
    '#type' => 'select',
    '#options' => $options,
    '#default_value' => !empty($search_page['settings']['apachesolr_search_search_type']) ? $search_page['settings']['apachesolr_search_search_type'] : '',
    '#access' => !$core_search,
    '#description' => t('Use this only when filtering on a value from the search path.
      For example, select Taxonomy Term to filter on a term ID (search/taxonomy/%).'),
    '#ajax' => array(
      'callback' => 'apachesolr_search_ajax_search_page_default',
      'wrapper' => 'dynamic-search-page',
      'method' => 'replace',
    ),
  );