I've never encountered any issues with CSS and IE before, and, while at home and work I mainly use Firefox, I do web application development so I have to test everything in IE too. Looking through your CSS code, I suspect the culprit is a single line:

filter: progid:DXImageTransform.Microsoft.Shadow(color=gray,direction=135);

It is in http://image4.flhurricane.com/cyclone/stylesheets/flhurricane.css and is the only non-standard CSS item in there that I could see, plus, since it calls DirectX stuff, is a likely culprit to crash on some systems and not others.

--RC