Mount DVD-RW step:

11)make sure the device dvdrecorder is hdc (from the output of dmesg)
2)make sure there is a device named hdc in /dev(otherwise you would get an eror "device does not exist")
3)If there is no device hdc in /dev(but your dvdrecorder is shown as hdc),you might have to create using MAKEDEV
a tutorial:http://www.linux.com/guides/sag/device-list.shtml
4)Are you trying to mount an empty drive?(you should have no problems),
but if you are trying to mount a audio cd rom,you might get an error(because audio cds do not have a filesystem)
also try mounting with a verbose option
search the log messages in /var/log to find any errors regarding the mount
you can also try
mount -t iso9660 /dev/hdc /mnt/dvdrecorder (or) with the fstab entry:
/dev/hdc /mnt/dvdrecorder iso9660 ro 0 0
you can install 'Ivman' too.....

Pls check your mountpoint :)