Adding the /etc/udev/rules.d/50-udev.rules file described above by Andi T. and rebooting has fixed this for me.
-- Wrong group for IDE cdrom/cdwriter/dvd devices https://launchpad.net/bugs/75753 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
