I posted this question last week with no reply. Could someone check whether cdrdao in FC6t2 works as a normal user? For example, try a fake blank operation by putting a CD-RW in the drive and running
eject -t ; cdrdao blank --device /dev/cdrom --simulate
as a normal user. In FC5 this gives the error message
cdrdao: Operation not permitted. Cannot send SCSI cmd via ioctl
as mentioned in