Condition worked in 4.0.1, but not in 4.0.2

[utahraves]

This was the same conditional IF command I was using on 4.0.1, upgraded and now it no longer works?
Template: Postbit

<vb:if condition="(THIS_SCRIPT == showthread) AND (($post[postcount] % 5) == 0)">
<div class="attachments" align=center>
...
</div>
</vb:if>

The code is to display a banner after every five posts only in SHOWTHREAD (postbit shows up as private messages too).

Even taking out the "THIS_SCRIPT == showthread) AND" did not resolve the issue.
Please help