SSL certificates are issued to an organization, based upon your site's fully formed domain, such as www.blackbaud.com. If you access https://XXXX.bbnc.bbcust.com, you will get an SSL error, and if you expand and look at the details of the error message, it will say that you are a URL that is different than the URL on the SSL certificate. This is rememdied by always browsing to the site using its fully formed domain.