The site was migrated to a new server last night and a new SSL certificate was installed. This server is much faster and has fewer accounts on it so response time is much greater.
At least one member received a "certificate expired" notifications while making a payment. That certificate was upgraded this morning. If you received this error, rest assured you took no real risk as our form collects no sensitive information. Your sensitive information (credit and bank numbers) is collected by the payment processor on a site that is behind bank grade security. You should not receive the "certificate expired" notification at this point.