It's always amusing when I hear of outfits that don't want to upgrade from Netscape 4.x ... don't they realise that even Netscape have declared it fundamentally broken (including in matters of rendering HTML) and scrapped the entire codebase? Maybe you should tell them so...🙂
Having a quick glance at the source, I see broken HTML, however.
<table>
<td bgcolor="#CC0033" align=middle><font size=5 color=white>
<center><input type = image src =' images/log-in.gif'
border = 0 alt =' Log In'></a></center> </td>
</table>
(Missing <tr></tr> pair). After fixing that I get code that's accepted by my HTML code validator (21 warnings notwithstanding) though it's unable to justify giving it a DOCTYPE imprimatur (I think becuase of the heavy use of both <span> and <font> entities).