wp_list_pages is not filtered

I’m trying to filter a sidebar generated by wp_list_pages so that users can only see what they have access rights to. However, the code below is having no filtering effect: everyone can see everything, regardless of their user permissions (or even if they are logged out). I’m sure I’m overlooking something simple; can someone help me figure out how to filter this sidebar?

<section id="content" class="center">
<h2 class="pagetitle">Sidebar Test</h2>
&lt;?php
attach_s2member_query_filters();

echo &#039;
<div class="coursewidget modulewidget sidebarwidget">
<h3 class="coursewidgettitle">My Courses</h3>
';

$modargs = array(
'post_type' =&gt; 'tu_level',
'title_li' =&gt; '',
);
echo '<ul class="courselist">';
wp_list_pages( $modargs ); 
echo '</ul>';

echo '</div>';

detach_s2member_query_filters();
?&gt;
</section>