Pulling up the response headers with FF and the web developer toolbar, one line stands out for the CSS file.
"text" all by itself is NOT a valid mime-type, and that's 100% guaranteed why it's screwing up. It should say "text/css" there, and this means the server is misconfigured; As such ride whoever DOES maintain the back-end's backside about the server being trash.
Though it's Windows IIs, so automatically it's trash -- this is just trashier than most. Say it with me people "*nix is for servers, Windows is for desktops, and never shall the twain meet!" Of course, if it was a *nix server running Apache I could probably just give you a .htaccess entry to fix it.
Mime-type in the HTTP response headers always trumps what you say in your code, or at least is supposed to.
that said, i'm surprised there aren't ENDLESS design issues with the page given the presence of this:
<meta content="MSHTML 6.00.2900.2627" name="GENERATOR" />
Especially with the nonsensical/broken heading orders, clearing div nonsense, HTML 3.2 style tags intermixed with 4, lack of XHTML closings, presentational images in the markup, lack of proper semantics (like say putting the quote in a BLOCKQUOTE?), etc, etc...