if you're using grub, go to your linux entry to the line starting with kernel and add ide_channel=ide-scsi to the end of it (look below at the code in bold for examples of this).
title Red Hat Linux (2.4.X)
kernel /boot/vmlinuz-2.4.X ro root=/dev/hda11 hdb=ide-scsi hdc=ide-scsi
if you're using lilo, i have no idea and the only suggestion i can think of would be to google something like "lilo emulate scsi" or something similar.
you'll probably need a reboot after this. plus you'll most likely need to re-link your /dev/cdrom or /dev/cdrom1 link, which ever one would be used for the combo burner.