Check your devices with dmesg|grep sr
The master device on your ide cable is sr0 and the slave sr1, unless you have a third drive which would then be sr2.
If you mount something at /dvd you should also check if it exists, else: mkdir /dvd

For dvd's add this to your /etc/apt/sources.list:
deb ftp://ftp.nerim.net/debian-marillat/ unstable main
Then do:
dselect update
apt-get -s install libdvdcss2 (remove the -s if it looks ok)

What are these lines doing?

/dev/cdaudio /cdaudio iso9660 defaults,ro,user,noexec,noauto 0 0
/dev/cdrom1 /mnt/auto/cdrom1 auto users,noauto,exec,ro 0 0
AFAIK cdaudio is for some programs that look for the disc there but I don't use it since AlsaPlayer uses sr0 just fine. Besides audio cd's can't be mounted anyway.
The /mnt/auto/cdrom1 is for automounting but you have to check if you have the directory and create it if needed with mkdir /mnt/auto/cdrom1. That said, I don't use automounting either so I'm not sure about this.