The old Comodo certificate signing process for a single domain
always produced a certificate with a Subject Alternate Name (SAN).
Both www.domain.buffalo.edu and domain.buffalo.edu were included in
each single domain certificate. If you requested
www.domain.buffalo.edu you would get a certificate for both
www.domain.buffalo.edu and domain.buffalo.edu. Likewise if you
requested domain.buffalo.edu you would get a certificate for both
domain.buffalo.edu and www.domain.buffalo.edu.
This is no longer the case. If you need a certificate with
both names you must create a CSR with a SAN field for the second