I’m guessing you have something like the following currently in your header.php file:
[code:48q2dhd1]<div id="mainmenu">
<ul>
<?php wp_list_pages(); ?>
</ul>
</div>[/code:48q2dhd1]
Try removing that and replacing it with:
[code:48q2dhd1]<?php suckerfish(); >[/code:48q2dhd1]
If that doesn’t work, then post back here and I’ll take another look.
If you can’t find that chunk of text above, then try looking in other template files as there is definitely something resembling that somewhere in your theme.
If you do post back, it would be more helpful if you could provide the HTML rather than a screenshot as that is where the problem lies.