Does this link work for you?
OK, I'm having trouble with a server here at work, and I'm 90% sure it's a problem with the secure certificate on the server and not the firewall (like the guy at InstantSSL keeps saying it is). Head to this link. You'll probably get SSL certificate errors, if it lets you through, but please post a comment and let me know if it lets you through and you see some standard disclaimer text. Please post with what browser and operating system (and versions) you are using so I can verify the problem. Thanks!
Update: If you can't get to the above address (and you've tried a few browsers), try this one.