If anyone is using this with vB 4.x, you can make the closed notice show up like this...
In the FORUMDISPLAY template, find
{vb:raw navbar}
and insert this underneath it:
PHP Code:
<vb:if condition="!$foruminfo[allowposting]">
<div style="text-align: center; font-weight: bold; color: red;">
<!-- your closed message here -->
The message board is not currently accepting posts. Please see the FAQ for more information.
</div>
</vb:if>
Still works like a charm.