Adveristing Table?

Hello, as you know i own http://www.mobiphobia.com basically ive put some advertising space @ the bottom of the page, well anyway on my brothers computer it seems to appear to the right side of the forum therefore squashes the whole of the forum up :S ?
Ive used table etc to do this here is the code :

<td><div align="center">
<table width="350" height="50" border="0" align="center">
<tr>
<td><a href="mailto:admin@mobiphobia.com"><img src="/advertise.jpg" width="140" height="50" border="0"></a></td>
<td><a href="mailto:admin@mobiphobia.com"><img src="/advertise.jpg" width="140" height="50" border="0"></a></td>
<td><a href="http://www.interfans.org"><img src="/interf_01.jpg" width="140" height="50" border="0"></a></td>
<td><div align="right"><a href="http://www.siansmobiles.co.uk"><img src="/siansbanner.gif" width="140" height="50" border="0"></a></div></td>
<td><a href="mailto:admin@mobiphobia.com"><img src="/advertise.jpg" width="140" height="50" border="0"></a></td>
<td><a href="mailto:admin@mobiphobia.com"><img src="/advertise.jpg" width="140" height="50" border="0"></a></td>
</tr>
</table>
</div></td>

This is put into the "Footer" template
Any ideas why it squashes the forums up ?
90% of people i ask it just appears normally @ the bottom it only seems to be his that does this!
Does it happen to any of you ?