Don't forget to include the <span> </span> tags.
PHP Code:
<div id="navMain">
<ul>
<?php if ($_SESSION['customer_id']) { ?>
<li><a href="<?php echo zen_href_link(FILENAME_LOGOFF, '', 'SSL'); ?>"><span><?php echo HEADER_TITLE_LOGOFF; ?></span></a></li>
<?php
} else {
if (STORE_STATUS == '0') {
?>
<li><a href="<?php echo zen_href_link(FILENAME_LOGIN, '', 'SSL'); ?>"><span><?php echo HEADER_TITLE_LOGIN; ?></span></a></li>
<?php } } ?>
<li><a href="<?php echo zen_href_link(FILENAME_ACCOUNT, '', 'SSL'); ?>"><soan><?php echo HEADER_TITLE_MY_ACCOUNT; ?></span></a></li>
<?php if ($_SESSION['cart']->count_contents() != 0) { ?>
<li><a href="<?php echo zen_href_link(FILENAME_SHOPPING_CART, '', 'NONSSL'); ?>"><span><?php echo HEADER_TITLE_CART_CONTENTS; ?></span></a></li>
<?php }?>
</ul>
</div>