Troubles using wp_list_pages

Hey guys,

I’ve got some issues using the wp_list_pages template tag twice on one HTML page, once in the page.php and once in the sidebar.php (doesn’t matter if hardcoded or as widget).

First thing I would like to do is a “table of content” with all subpages of the current page:

$sub_pages = wp_list_pages('title_li=&child_of='.$post->ID.'&sort_colum=post_name&echo=0');
if($sub_pages) {
    echo '<div style="border: 1px solid red; margin: 10px auto; width: 90%;">';
    echo '<div style="margin: 10px; font-weight: bold;">Inhaltsverzeichnis <span style="font-weight: normal;">[<a href="#" onclick="switchDirectory();" id="switcher">Anzeigen</a>]</span></div>';
    echo '<ol id="directory" class="directory-hide">';
    echo $sub_pages;
    echo '</ol>';
    echo '</div>';
}

Second thing is a list will alle subpages of the post->parent page in the Sidebar:

<li>
                <ul>
<?php $related_pages = wp_list_pages('title_li=&depth=1&child_of='.$post->post_parent.'&sort_colum=post_name&echo=1'); ?>
                </ul>
            </li>

If I execute both scripts for its own, they work perfect. But if I have both on one page, the HTML output stops directly before the second call.

Unfortunately there are no PHP errors and the $post variable is correct.

Anyone an idea what the problem can be?

THX in advance!

Cheers
Whooper