Can certain box appear in certain forum / catagories?

[valdet]

Try this conditional

<if condition="$forum[forumid] == X"></if>

so now your box would be like this:

<!-- iRapid Links Checker starts here -->

<if condition="$forum[forumid] == X">
<if condition="$post[postcount] == 1">

<iframe name="home" src="http://www.irapid.co.uk/test/link.html" border="0" frameborder="0" width="500" height="149"></iframe>

</if>
</if>
<!-- iRapid Links Checker starts here -->

I hope that helps you out.

Best regards,
Val.