Yes, you coded it to show like that.
You need to remove the extra td & div tags.
Edit it like this:
Code:
$affiliates = "<!-- Affiliates -->
<table class='tborder' cellpadding='$stylevar[cellpadding]' cellspacing='$stylevar[cellspacing]' border='0' width='100%' align='center'>
<td class='tcat' align='center' width='100%'>Affiliates</td>
<tr>
<div class='fieldset' style='margin:0px'>
<td class='alt1' align='center'>
<a href='http://google.com/'><img border='0' src='http://www.xleagues.net/test.jpg' alt='' /></a>
<a href='http://google.com/'><img border='0' src='http://www.xleagues.net/test.jpg' alt='' /></a>
</td>
</div>
</tr>
</table>
<!-- / Affiliates -->
<br />";
$Position = '$navbar';
$vbulletin->templatecache['FORUMHOME'] = str_replace($Position, $Position . ' $affiliates', $vbulletin->templatecache['FORUMHOME']);