Child menu items don't appear when current page is front page

The current version of Menu block does not show subnodes of the frontpage until they are selected. I've created a modified version of menu_tree_prune_tree() in the menue_block.module file. Perhaps this will be implemented in next releases of this really useful module.

Here is the code:

/**
 * Prune a tree so that it begins at the specified level.
 *
 * This function will follow the active menu trail to the specified level.
 *
 * @param $tree
 *   array The menu tree to prune.
 * @param $level
 *   int The level of the original tree that will start the pruned tree.
 * @param $parent_item
 *   array The menu item that should be used as the root of the tree.
 * @return
 *   void
 */
function menu_tree_prune_tree(&$tree, $level, $parent_item = FALSE) {
...

  // Trim the upper levels down to the one desired.
  for ($i = 1; $i < $level; $i++) {
    $found_active_trail = FALSE;
    // Examine each element at this level for the active trail.
    foreach ($tree AS $key => &$value) {
      if ($tree[$key]['link']['in_active_trail']) {
        // Get the title for the pruned tree.
        menu_block_set_title($tree[$key]['link']);
        // Prune the tree to the children of the item in the active trail.
        $tree = $tree[$key]['below'] ? $tree[$key]['below'] : array();
        $found_active_trail = TRUE;
        break;
      } else {
		if($tree[$key]['link']['link_path'] == '<front>' && drupal_is_front_page()) {
			// Get the title for the pruned tree.
			menu_block_set_title($tree[$key]['link']);
			// Prune the tree to the children of the item in the active trail.
			$tree = $tree[$key]['below'] ? $tree[$key]['below'] : array();
			$found_active_trail = TRUE;
			break(2);
		}
	  }
    }
...
}

By the way: Is there a update-save method to overwride methods of a module/core (e.g. in the template.php)?

Cheers,
Rafael Kutscha