If you are trying to keep X from starting, you could just temporarly modify the /boot/syslinux/syslinux.cfg file by removing "autoexec=xconf;kdm" (or whatever it says for the boot choice you use).
To keep X from restarting when you press CTRL-ALT-BACKSPACE, modify your xorg.conf by either modifying or adding the following line:
Code:Section "ServerFlags" Option "DontZap" "yes" EndSection


