You can do it without the rescue CD. The idea is to get into run level 1.
pick "e" to edit the grub boot command
pick
kernel /boot/vmlinuz-2.4.18-4 ro root=LABEL=/
and (I believe it's "e" again?) there's some option to edit this one.
add " 1" at the end so it reads
kernel /boot/vmlinuz-2.4.18-4 ro root=LABEL=/ 1
that is the run level. run level 1 gets you straight to a (root) shell without starting any network services (and without hanging). Your chance to set it right.
For jobs that actually require a rescue CD (say, you overwrite your master boot record), the RH8 or 9 rescue mode gets the job done, but there are better ones around. I myself maintain
http://www.phenix.bnl.gov/~purschke/RescueCD/
and there are several references to other nice Rescue CD sets in there.
Good luck
mlp