parent menu items do not get synchronized

If I add or update a node linked to a child term, the parent menu -item does not get updated while it may change if "Display number of items" is checked (as well as "Use 'all' at the end of URL") (or if "Hide empty terms" is checked)

Example:
Menu looks like:
term 1 (3)
- term 1.1 (2)
- term 1.2 (1)
term 2 (4)

If I add a node tagged with term 1.1 the updated menu should look like:
term 1 (4)
- term 1.1 (3)
- term 1.2 (1)
term 2 (4)

I quickly solved it by adding the following lines (no guarantee that it works for all combinations of settings)

function _taxonomy_menu_nodeapi_helper($op, $terms = array()) {
  $org_op = $op; // NEW LINE
  foreach ($terms as $key => $tid) {
    ...
    if ($menu_name && $vocb_sync && ($menu_num || $hide_empty)) {
      switch ($op) {
        ...
      }
      taxonomy_menu_handler($op, $args);
      // NEW LINES: update parent menu items as well if display_num or hide_empty
      foreach ($term->parents as $parent) {
        _taxonomy_menu_nodeapi_helper($org_op, array($parent));
      }
      // END OF NEW LINES
    }
  }
}