The secure payment certificate for HDCN had expired in early March. This resulted in an error message of "untrusted connection" on trying to pay the renewal fee for HDCN via "http://www.hdcn.com/subinfo.htm", the renewal link.
This certificate renewal is in progress and the new certificat should be in place later today, 13 March 2012. If you had tried to renew and had run into this problem, please try again. The above error message will no longer be displayed once the secure certificate renewal has been activated.