Header Navigation Link Disappears After Log in

[bluelightnin6]

I added an "about us" link to my top header navigation through editing my tpl_header.php file. My "about us" link now looks and works properly when viewing the site as a guest, however this "about us" link disappears when i log in to my site as a customer. i am assuming i have placed the link in my file incorrectly. can someone point me in the right direction please?

<!--bof-navigation display-->
<div id="navMainWrapper">
<div id="navMain">
    <ul class="back">
   
    <li><?php echo '<a href="' . HTTP_SERVER . DIR_WS_CATALOG . '">'; ?><?php echo HEADER_TITLE_CATALOG; ?></a></li>
<?php if ($_SESSION['customer_id']) { ?>
    <li><a href="<?php echo zen_href_link(FILENAME_LOGOFF, '', 'SSL'); ?>"><?php echo HEADER_TITLE_LOGOFF; ?></a></li>
    <li><a href="<?php echo zen_href_link(FILENAME_ACCOUNT, '', 'SSL'); ?>"><?php echo HEADER_TITLE_MY_ACCOUNT; ?></a></li>
<?php
      } else {
        if (STORE_STATUS == '0') {
?>
<li><a href="http://www.moebow.com/about-us-ezp-3.html">About Us</a></li>
    <li><a href="<?php echo zen_href_link(FILENAME_LOGIN, '', 'SSL'); ?>"><?php echo HEADER_TITLE_LOGIN; ?></a></li>
    
<?php } } ?>

<?php if ($_SESSION['cart']->count_contents() != 0) { ?>
    <li><a href="<?php echo zen_href_link(FILENAME_SHOPPING_CART, '', 'NONSSL'); ?>"><?php echo HEADER_TITLE_CART_CONTENTS; ?></a></li>
    <li><a href="<?php echo zen_href_link(FILENAME_CHECKOUT_SHIPPING, '', 'SSL'); ?>"><?php echo HEADER_TITLE_CHECKOUT; ?></a></li>
    
<?php }?>
</ul>
</div>
<div id="navMainSearch"><?php require(DIR_WS_MODULES . 'sideboxes/search_header.php'); ?></div>
<br class="clearBoth" />
</div>

<!--eof-navigation display-->