CD/DVD-drives disappearing

Hi, people. I've got strange problem with my SuSE 10.0. If CD or/and DVD left inside of the drive(s) while system boots, then, after system is booted, CD-RW drives or/and DVD-RAM drives device file(s) is/are missing from /dev. They simply disappear. No /dev/hdc (CD-RW) or/and no /dev/hdd (DVD-RAM). I'm new to SuSE and it took me a while to find out that device files are missing. First I noticed that sometimes disks doesn't mount. :-\ Can anyone tell me why does system "hide" those files. Is this a bug or a feature (though I doubt it could be a feature)? Thanks for your attention, Roma.