[CentOS] DVD drive ownership/permissions group ownership = mail?

I can change the group ownershipp of the DVD drive, but if I log out &
in again it changes back. Is there a way to make a change permanent?
How could I figure out what process is changing this back?

ls -la /dev/scd0
brw-rw---- 1 root mail 11, 0 Nov 12 15:17 /dev/scd0


mahalo,
Dave