search in forumdisplay template for this code:
Code:
<thead>
<tr align="center">
<td class="thead"> </td>
<td class="thead" width="100%" align="$stylevar[left]">$vbphrase[forum]</td>
<td class="thead">$vbphrase[last_post]</td>
<td class="thead">$vbphrase[threads]</td>
<td class="thead">$vbphrase[posts]</td>
<if condition="$vboptions[showmoderatorcolumn]">
<td class="thead">$vbphrase[moderator]</td>
</if>
</tr>
</thead>
if you find it or something similar, remove it