Hi purpleburple, I'll try to answer your questions
1. Does anyone know what /dev/sr0 is?
A) what this means is that you have a device that is SCSI recorder with an ID of 0 that's why you'll see this entry
/dev/sr0
2. How come back in Redhat even with scsi enabled and I could burn cd's I only had to type /mnt/cdrom to mount a cd and now I have to type mount /dev/sr0 /mnt/cdrom??
A) there is a chance that RedHat created the symlink that neo77777 mentions and there was no need to mount the device to the mounting point with mount /dev/sr0 /mnt/cdrom
3.Also after mounting and then umounting the cd I give the eject command and get this error message>
eject: unable to eject, last error : Input/output error
A)Just make sure that when you are ejecting the device you are not sitting on it. What I mean is that if you are in mnt/cdrom and try to eject from here Linux will not let you. You need to cd to mnt and eject from there.
I hope this helps.