you need to edit the rate_form.html Template like this:
<!-- start rate_form.html -->
<br />
<table width="100%" border="0" cellspacing="1" cellpadding="3" class="head1">
<tr>
<td valign="top" >{rate}</td>
</tr>
<tr>
<td class="row1"><table border="0" align="center" cellpadding="1" cellspacing="0">
<tr ><form method="post" action="{self}">
<td>
<input type="hidden" name="action" value="rateimage" />
<input type="hidden" name="id" value="{image_id}" />
<input type="hidden" name="rating" value="1" />
<input src="{template_url}/images/smilies_1.gif" type="image" name="Mangelhaft" value="Mangelhaft" alt="Mangelhaft" title="Mangelhaft"/>
</td></form><form method="post" action="{self}">
<td>
<input type="hidden" name="action" value="rateimage" />
<input type="hidden" name="id" value="{image_id}" />
<input type="hidden" name="rating" value="2" />
<input src="{template_url}/images/smilies_2.gif" type="image" name="Ausreichend" value="Ausreichend" alt="Ausreichend" title="Ausreichend"/>
</td></form><form method="post" action="{self}">
<td>
<input type="hidden" name="action" value="rateimage" />
<input type="hidden" name="id" value="{image_id}" />
<input type="hidden" name="rating" value="3" />
<input src="{template_url}/images/smilies_3.gif" type="image" name="Befriedigend" value="Befriedigend" alt="Befriedigend" title="Befriedigend"/>
</td></form><form method="post" action="{self}">
<td>
<input type="hidden" name="action" value="rateimage" />
<input type="hidden" name="id" value="{image_id}" />
<input type="hidden" name="rating" value="4" />
<input src="{template_url}/images/smilies_4.gif" type="image" name="Gut" value="Gut" alt="Gut" title="Gut"/>
</td></form><form method="post" action="{self}">
<td>
<input type="hidden" name="action" value="rateimage" />
<input type="hidden" name="id" value="{image_id}" />
<input type="hidden" name="rating" value="5" />
<input src="{template_url}/images/smilies_5.gif" type="image" name="Sehr gut" value="Sehr gut" alt="Sehr gut" title="Sehr gut"/>
</td></form>
</tr>
</table></td>
</tr>
</table>
<!-- end rate_form.html -->