This is a post just to advice other people about a possible problem they can face moving to kernel 2.6
I kernel 2.4.x in order to use an ide burn unit you need to add hdd=ide-scsi emulation as kernel parameter.
Now kernel 2.6 support natively ide burner and if you leave the option ide-scsi you cd unit disappear.
In my case using the old hdd=ide-scsi parameter result in not creating the device in /dev, so no cdrom
The correct parameter now is hdd=ide-cd
It is quite difficoult to find out about this error since nothing show at boot-up and there is just one line in /var/log/kernel as advice to switch to ide-cd
I saw in another post
people saying that is not necessary or they have to use the old ide-scsi parameter due to problems.
So it seem that not always the unit disappear