I am currently using Internet Explorer 9 on Windows Server 2008. It seems that all https-requests to cdn.sstatic.net (SE's cookieless domain) fail. The corresponding http-request works fine for me. This is at least for the following urls (by going to the codegolf login page):
Inspecting the requests in IE9's developer console shows that the request was terminated before it even got to send the headers. My browser gives the dns-error page, which either means the hostname could not be resolved, or in case of https, that the protocol required is not enabled. As far as I am aware, DNS works exactly the same for http as it does for https, and since the http-link works fine, it is not an issue with DNS. In the settings SSL 3 and TLS 1.0 are enabled however, and the codegolf login page itself will load without an error page. I have logged in from this computer/network/operating system/browser and back then the page was working. That's also the only reason why I am able to post here.
I can't completely be sure that this isn't the company firewall acting up, but usually that blocks requests on both http and https. Besides that it normally gives me a message "This page is blocked, because it contains 'Humor'" or something along those lines. It could as well be a bug between IE9 and the setup of the cdn server. I am aware there are some similar questions like this one, but they either blame China, mixed content or temporary outage of the cdn server. Neither of them are the case here.