This site is running vB3 and everything uses tables. vB4 uses divs so that you may control the look of your site via CSS.
You could try something like this in your postbit/postbit_legacy template:
HTML Code:
<h2 class="posttitle icon">
<vb:if condition="$show['messageicon'] AND $post['icontitle'] != 'Default' "><img src="{vb:raw post.iconpath}" alt="{vb:raw post.icontitle}" /> </vb:if>{vb:raw post.title}
</h2>
See if that works.