Can you show us the resulting source from your site (directly from your browser), please. Something like this (include all TDs pertaining to the one link say, Contact Us link)...
<td class="TabLeftSide"><img src="/skin1/images/spacer.gif" class="TabSide" alt="" /></td>
<td class="Tab"><a href="help.php?section=contactus&mode=update"> Contact Us</a></td>
<td class="TabRightSide"><img src="/skin1/images/spacer.gif" class="TabSide" alt="" /></td>
Also have you modified the cart in any way? Have you purchased a skin, for example? Or a URL modifier?
Regards,
Doms