postbit confusion

[Lionel]

I am trying to display showtread for news.
In the postbit templates, I did:

<!-- message -->
<!--lionel--><table width="100%" border="0" cellspacing="0" cellpadding="5"><tr> <td valign="top"> <if condition="$show['thumbnailattachment']"> <table align="right"><tr><td> <fieldset class="fieldset"><legend>News Images</legend>
<div style="padding:$stylevar[formspacer]px">$post[thumbnailattachments]</div> </fieldset></td></tr></table></if><div>$post[message]</div></td></tr></table> <!--/lionel-->
<!-- / message -->

<if condition="$show['attachments']">
<!-- attachments -->
<div style="padding:$stylevar[cellpadding]px">


<!--lionel--><!-- <if condition="$show['thumbnailattachment']">
<fieldset class="fieldset">
<legend>News Images</legend>
<div style="padding:$stylevar[formspacer]px">$post[thumbnailattachments] </fieldset>
</if> --> <!--/lionel-->

It post very well as per attachment. But why would the subsequent post display the empty fieldsets?

Also is it possible to make the change for the first post only, others to display like normal (the red section above that has been commented out).

Thank you for any help.