you have to remove it from footer.html, and then add to all main templates into this table: <table width="640" border="0" cellspacing="0" cellpadding="0" class="tablebottom">
<tr>
<td width="6"><img src="{template_url}/images/footer_left.gif" width="6" height="19" alt="" /></td>
<td width="405"> </td>
<td width="225"> </td>
<td width="6"><img src="{template_url}/images/footer_right.gif" width="6" height="19" alt="" /></td>
</tr>
</table>