[CFodder]

Well I've checked and double checked, am pretty sure I've done it all as you've described. Here's my code for the Home Tab:

<vb:if condition="$vboptions['selectednavtab'] == 'vbcms'">
<li class="selected">
<vb:if condition="$vboptions['vbcms_url']">
<a class="navtab" href="{vb:raw vboptions.site_tab_url}{vb:raw session.sessionurl_q}"><img src="/images/navbar/Home.png" Height="24" Width="24" border="0" align="top" title="Home" alt="Home" /> {vb:rawphrase site}</a>
<vb:else />
<li><a class="navtab" href="{vb:raw vboptions.site_tab_url}{vb:raw session.sessionurl_q}"><img src="/images/navbar/Home.png" Height="24" Width="24" border="0" align="top" title="Home" alt="Home" /> {vb:rawphrase site}</a></li>
</vb:if>