You may wish to do a dirty remaster when testing out the booting of the cd adjust paths as nessecary

unpacks the cd to /tmp/cd

rm -rf /tmp/cd
rm -rf /tmp/cd-orig
mkdir /tmp/cd-orig
mkdir /tmp/cd
sudo mount -o loop /storage/isos/skolelinux/debian-edu-etch-test.iso /tmp/cd-orig
rsync -v -a -H --exclude=TRANS.TBL /tmp/cd-orig/ /tmp/cd/
chmod -R u+rw /tmp/cd
sudo umount /tmp/cd-orig

recreates the iso

cd /tmp/cd
rm md5sum.txt
md5sum `find -follow -type f` > md5sum.txt

#new image
cd /tmp
rm -rf  /storage/isos/skolelinux/remastered.iso
mkisofs -o /storage/isos/skolelinux/remastered.iso -r \
        -b isolinux/isolinux.bin -c isolinux/ \
        -no-emul-boot -boot-load-size 4 \
        -boot-info-table /tmp/cd