Always best to name it by an identifier as well, especially in XHTML. Some browsers accept name, some accept id, some accept both, but XHTML makes it a little more strict in some browsers

The code you are using for Internet Explorer's conditional statements is fine. To any other browser it looks like a comment, but to Internet Explorer it checks the version. I'm not sure why it's not working, but check the CSS file exists possibly? I can test it when I get home, but if you just Google "HTML conditional statements", take an MSDN page and it should show you how to do > and < versions. So you wat IE < 7, but there's a proper way of doing it.