Is there a way to disable the sub-menu in the Nav block?

I like this module, but I want the users to click on the main index page link to see all the other index pages. I don't want those indexes show show up in the nav block.

I tried commenting out a portion of the code:

function indexpage_menu($may_cache) {
global $user;
$items = array();
if ($may_cache) {
$items[] = array('path' => 'indexpage', 'title' => t('main index page'), 'callback' => 'indexpage_page', 'access' => user_access('access indexpage'), 'type' => MENU_NORMAL_ITEM);
}
/* $result = @db_query("SELECT DISTINCT type FROM {node} ORDER BY type");
while ($node = db_fetch_object($result)) {
array_push($items, array('path' => 'indexpage/'.$node->type, 'title' => t("index page for %s", array("%s" => $node->type)), 'access' => user_access('access indexpage'), 'type' => MENU_NORMAL_ITEM));
} */
return $items;
}

But that doesn't seem to have done the trick. Am I looking at the wrong part?