I am using this code to list pages in the menu.
<?php wp_list_pages('depth=1&title_li=&sort_column=menu_order&excludetree=');?>
</ul>
</li>
<ul id="submenu"><li><?php
/*http://codex.wordpress.org/Template_Tags/wp_list_pages#List_subpages_even_if_on_a_subpage*/
if($post->post_parent)
$children = wp_list_pages("title_li=&child_of=&sort_column=menu_order, post_title".$post->post_parent."&echo=0");
else
$children = wp_list_pages("title_li=&child_of=".$post->ID."&echo=0");
if ($children) { ?>
<ul>
<?php echo $children; ?>
</ul>
<?php } ?></li></ul>
</div>
The idea is for the menu to show the parent pages and it's children. It works on the parents page: http://www.metaphorm.org/new3/bio/ but if you go to a child page they disappear: http://www.metaphorm.org/new3/bio/artist-statement/
Obviously PHP is not my strong point.