[norvo]

Okay, I seem to have it more or less working. I used this code in the template-edit, maybe somebody can use it:

<!-- Begin Hack Sponsor -->
<if condition="!empty($forum[sponsorimg])">
<table cellpadding="0" cellspacing="0" border="0" class="tborder" width="100%" align="center"><tr><td>
<table cellpadding="6" cellspacing="1" border="0" width="100%">
<tr><td class="alt2">
<a href="$forum[sponsorurl]"><img src="$stylevar[imgdir_misc]/$forum[sponsorimg]" alt="$forum[sponsorname]" title="Proudly sponsored by $forum[sponsorname]" align="right" /></a>
<div style="padding: 6px; text-align: center;">Today's forum discussions are proudly sponsored by <a href="$forum[sponsorurl]">$forum[sponsorname]</a>.</div></td></tr>
</table></td></tr></table>
</if>
<!-- End Hack Sponsor -->