Here is an older way of doing this and your should be similiar in structure where your code should replace what I have in red. Added the navHead div inside logoWrapper
Code:
<!--bof-branding display-->
<div id="logoWrapper">
<div id="logo"><?php echo '<a href="' . HTTP_SERVER . DIR_WS_CATALOG . '">' . zen_image($template->get_template_dir(HEADER_LOGO_IMAGE, DIR_WS_TEMPLATE, $current_page_base,'images'). '/' . HEADER_LOGO_IMAGE, HEADER_ALT_TEXT) . '</a>'; ?></div>
<!-- begin top navigation -->
<div id="navHead">
<img src="includes/templates/test/images/spacer.gif" width="235" height="44" border="0" /></a>
<a href="index.php?main_page=XXXXX"><img src="includes/templates/test/images/spacer.gif" alt="XXXX" width="120" height="44" border="0" /></a>
<a href="index.php?main_page=XXXXXX"><img src="includes/templates/test/images/spacer.gif" alt="XXXXXX" width="125" height="44" border="0" /></a>
<a href="index.php?main_page=index&cPath=5"><img src="includes/templates/test/images/spacer.gif" alt="XXXXXXXX" width="125" height="44" border="0" /></a>
<a href="index.php?main_page=about_us"><img src="includes/templates/test/images/spacer.gif" alt="About Us" width="120" height="44" border="0" /></a>
<!-- end top nav --></div>
</div>
But you might look at ezpages and the header location to make this easier