Tabel-problem

Hvorfor virker denne tabel ikke ordentligt?

<table width="789" border="1" align="center" cellpadding="0" cellspacing="0" >
<tr>
    <td colspan="2"><img src="1.gif" alt="" width="284" /></td>

<td>
<table width="505" cellpadding="0" cellspacing="0" border="0">
<tr>
<td width="505" colspan="2"><img src="2.gif" width="505" alt="" /></td>
</tr>
<tr>
<td width="505" colspan="2"><img src="3.gif" width="505" alt="" /></td>
</tr>
</table>
</td>

</tr>
<tr>
<td width="28"><img src="pil.gif" width="28" alt="" /></td>
<td width="150">Menu</td>
<td width="481">Indhold</td>
<td width="130">Banner</td>
</tr>

</table>