I was still able to checkout but received this warning forcing me to create an exception in Firefox.
Secure Connection Failedwww.luminous-landscape.com
uses an invalid security certificate.
The certificate expired on 6/17/09 7:22 PM.
(Error code: sec_error_expired_certificate)
* This could be a problem with the server's configuration, or it could be someone trying to impersonate the server.
* If you have connected to this server successfully in the past, the error may be temporary, and you can try again later.