Table padding in IE

I got the following CSS and HTML which don't give the expected results in IE.

<style type="text/css">
.moduletable {
	border:1px solid #FF9900;
	padding:0 0 10px 0;
	margin:0;
}
</style>

<table cellspacing="0" cellpadding="1" align="center" class="moduletable">
  <tbody>
    <tr>
      <th valign="top">Main Menu</th>
    </tr>
    <tr>
      <td>
        <table width="100%" border="0" cellpadding="0" cellspacing="1">
          <tbody>
		    <tr align="left">
			  <td>
			    &nbsp;<a href="index.php?option=com_frontpage&amp;Itemid=1" class="mainlevel">Home</a>
              </td>
			</tr>
            <tr align="left">
			  <td>
			    &nbsp;<a href="index.php?option=content&amp;task=view&amp;id=20&amp;Itemid=54" class="mainlevel">About Us</a>
              </td>
	        </tr>
            <tr align="left">
		      <td>
		        &nbsp;<a href="index.php?option=content&amp;task=view&amp;id=17&amp;Itemid=41" class="mainlevel">Our Mission</a>
              </td>
		    </tr>
            <tr align="left">
		      <td>
			    &nbsp;<a href="index.php?option=content&amp;task=view&amp;id=21&amp;Itemid=55" class="mainlevel">What is PHP?</a>
              </td>
		    </tr>
            <tr align="left">
		      <td>
			    &nbsp;<a href="index.php?option=content&amp;task=category&amp;sectionid=2&amp;id=75&amp;Itemid=56" class="mainlevel">Group FAQ</a>
              </td>
	        </tr>
            <tr align="left">
		      <td>
			    &nbsp;<a href="index.php?option=com_contact&amp;Itemid=3" class="mainlevel">Contact Us</a>
              </td>
		    </tr>
          </tbody>
	    </table>    			
	  </td>
    </tr>
  </tbody>
</table>

I am trying to give the table with the moduletable class to have a bottom padding of 10px . This works perfectly well on Mozilla but nuthin happens on IE. Could someone point me to what I am doing wrong ?

cheers,
Jeffery

[Edit] The code is from a CMS system so I can't modify the existing HTML