copy the iso image to a partition and use the bootfrom=/dev/hd?/path/to/iso/k*.iso cheatcode and see if she boots, then post any error messages reguarding your cd-rom. replace ? with your hard drive and partition (i.e. a1)

'dmesg' 'udevinfo -q all -p /block/hd?' and 'hdparm /dev/hd?' might help aswell.
replace '?' with the minor number of your cd/dvd device (i.e. [a-z])

edit: sorry about the sloppy first post.