Whoops! IE7's incomprehensible error message.
You have to wonder just how well the security system of IE7 has been tested when they let an error message like this slip through. Go to a website with a self-signed SSL certificate and IE7 displays a page warning about it. Click on the "Continue anyway" link. then click the "Certificate Error" box in the ribbon area then click "Install Certificate" in the Certificates window that pops up. You are left with this: