I have noticed on the code you posted there seems to a couple lines that look very identical???
HTML Code:
<if condition="$foruminfo[sponsor_enabled] == 1 AND $vboptions[sponsor_global_enable_sponsorship] == 1">
<div align="center>
$vbphrase[sponsored_by] <a href="vB.Sponsors/link.php?f=$foruminfo[forumid]" title="$foruminfo[sponsor_name]" target="_blank">
<if condition="$foruminfo[sponsor_banner_enabled] == 1 AND $vboptions[sponsor_global_enable_banners] == 1">
<if condition="!empty($foruminfo[sponsor_banner_big])">
<img src="$foruminfo[sponsor_banner_big]" alt="$foruminfo[sponsor_name]" border="0" />
<else />
<img src="$foruminfo[sponsor_banner]" alt="$foruminfo[sponsor_name]" border="0" />
</if>
<else />
$foruminfo[sponsor_name]
</if></a>
</div>
</if>
Code in question below
<img src="$foruminfo[sponsor_banner_big]" alt="$foruminfo[sponsor_name]" border="0" />
<img src="$foruminfo[sponsor_banner]" alt="$foruminfo[sponsor_name]" border="0" />