To make only guest see the ads take this code and add it at the end of the postbit (_legacy) template.
Code:
<if condition="in_array($bbuserinfo[usergroupid], array(1))">
<if condition="$GLOBALS['adsense_position'] == $post['postcount']">
$spacer_open
<div style="padding:0px 0px $stylevar[cellpadding]px 0px">
<table class="tborder" cellpadding="$stylevar[cellpadding]" cellspacing="$stylevar[cellspacing]" border="0" width="100%" align="center">
<tr>
<td class="thead" align="left">Sponsored Links</td>
</tr>
<tr>
<td class="alt1" align="center">
<!-- ad code goes here -->
</td>
</tr>
</table>
</div>
$spacer_close
</if>
</if>
@UK Jimbo, do you allow me to translate/modify and post this modification @
www.vbhacks-germany.com (of course with your copyright)?