Tente o seguinte:
# echo 'SUBSYSTEM=="scsi", KERNEL=="scd[0-9]", ATTRS{type}=="5" GROUP="optical", MODE="0666"' > /etc/udev/rules.d/80-cdrom.rules
test the rule
# udevadm test $(udevadm info -q path -n /dev/sr0) 2>&1
load the rule
# udevadm control --reload-rules
Atualizar
Parece que o FC4 udev antecedeu o udevadm. Eu puxei uma tarball de udev-058-1 que acompanha o FC4 e suas regras de 50-udev relevantes para o dvd devem ser semelhantes a isto:
# old compat symlinks with enumeration
KERNEL=="sr[0-9]*", SYMLINK="cdrom%e"
KERNEL=="scd[0-9]*", SYMLINK="cdrom%e"
KERNEL=="pcd[0-9]*", SYMLINK="cdrom%e"
# do not seperate the next 2 lines!!
KERNEL=="hd[a-z]", BUS=="ide", SYSFS{removable}=="1", PROGRAM=="/etc/udev/scripts/ide-media.sh %k", RESULT=="floppy", SYMLINK="floppy%e", NAME{ignore_remove, all_partitions}="%k"
KERNEL=="hd[a-z]", BUS=="ide", SYSFS{removable}=="1", RESULT=="cdrom", SYMLINK="cdrom%e"
KERNEL=="hd[a-z]", BUS=="ide", SYSFS{removable}=="1", PROGRAM=="/etc/udev/scripts/check-cdrom.sh %k DVD", SYMLINK="dvd%e"
KERNEL=="sr[0-9]*", BUS=="scsi", PROGRAM=="/etc/udev/scripts/check-cdrom.sh %k DVD", SYMLINK="dvd%e"
KERNEL=="hd[a-z]", BUS=="ide", SYSFS{removable}=="1", PROGRAM=="/etc/udev/scripts/check-cdrom.sh %k CD-R", SYMLINK="cdwriter%e"
KERNEL=="sr[0-9]*", BUS=="scsi", PROGRAM=="/etc/udev/scripts/check-cdrom.sh %k CD-R", SYMLINK="cdwriter%e"
KERNEL=="hd[a-z]", BUS=="ide", SYSFS{removable}=="1", PROGRAM="/etc/udev/scripts/check-cdrom.sh %k DVD-R", SYMLINK="dvdwriter%e"
KERNEL=="sr[0-9]*", BUS=="scsi", PROGRAM=="/etc/udev/scripts/check-cdrom.sh %k DVD-R", SYMLINK="dvdwriter%e"
# rename sr* to scd*
KERNEL=="sr[0-9]*", BUS=="scsi", NAME="scd%n"
KERNEL=="hd[a-z]*", BUS=="ide", SYSFS{removable}=="1", NAME{ignore_remove}="%k"
Tente alterar a linha anterior ao anterior, que renomeia sr para scd e reinicialize.
KERNEL=="sr[0-9]*", BUS=="scsi", NAME="scd%n", MODE="0666"