Ci sono un sacco di colspan messi a caso che sballano il layout, prova così:
codice:
<TABLE WIDTH=100% BORDER=0 CELLPADDING=0 CELLSPACING=0 align=center>
<tr>
<td>

<TABLE WIDTH=98% BORDER=0 CELLPADDING=0 CELLSPACING=0 align=center>
<TR>
<TD background="img/sfgrey.gif" WIDTH=170 HEIGHT=70>[img]img/logo.gif[/img]</TD>
<TD background="img/sfgrey.gif"></TD>
<TD background="img/sfgrey.gif" WIDTH=475 HEIGHT=70 align="right"><div align="left">[img]img/banner.gif[/img]</div></TD>
</TR>
<TR><TD COLSPAN=3 background="img/sfbluline.gif" WIDTH=98% HEIGHT=9></TD>
</tr>
</table>

</td>
</tr>
<tr>
<td>

<TABLE WIDTH=80% HEIGHT=180 BORDER=0 CELLPADDING=0 CELLSPACING=0 align=center>
<TR>
<TD background="img/sfgrey.gif" WIDTH=120 align="center" valign="top">[img]img/btmEsplora.gif[/img]</TD>
<TD background="img/sfgrey.gif" align="center" valign="top">[img]img/btmChiedi.gif[/img]</TD>
<TD background="img/sfgrey.gif" align="center" valign="top">[img]img/btmricerca.gif[/img]</TD>
</TR>
</table>

</td>
</tr>
</table>