Getting two submit buttons on the subscription signup page

Hi,

I'm getting two submit buttons on the subscription signup page.
It was ok but this has happened since an upgrade so not sure where I have gone wrong. It is a free subscription so I have added my own button.

this is the code on the page

<table class="purchasetable">
<tbody>
<tr>
<td class="detailscolumn"> Test Company </td>
<td class="pricecolumn">Free </td>
<td class="buynowcolumn">
<form method="post" action="http://www.progressionmvl.com/learning-portal/">
<input id="_wpnonce" type="hidden" value="c8ba6d8421" name="_wpnonce">
<input type="hidden" value="/register/?action=subscriptionsignup&subscription=1" name="_wp_http_referer">
<input type="hidden" value="freesubscriptions" name="gateway">
<input type="hidden" value="subscriptionsignup" name="action">
<input type="hidden" value="1387540607:22:1:f525dae751d035982ee5ae06d9d96b54:0" name="custom">
<input type="image" border="0" alt="PayPal - The safer, easier way to pay online" src="http://91.109.6.72/~progress/wp-content/themes/progressionmvl/images/subscribeBtn.png" name="submit">
<input type="image" border="0" alt="PayPal - The safer, easier way to pay online" src="http://91.109.6.72/~progress/wp-content/themes/progressionmvl/images/subscribeBtn.png" name="submit">
</form>
</td>
</tr>
</tbody>
</table>

Any help - greatly appreciated.

Jo