Ah, sorry, misunderstood the question. Thought it was the main install that was failing and would an emergency disk help correct it.
What's the script error? Whenever these sorts of things happen I try to look at the script itself to see if I can work around the problem. And since the end product is a floppy that mounts the CD (and finishes booting from CD?) you can try to work to that manually.
I have a vague recollection of the emergency disk installer copying a fixed directory or file from your hard disk to floppy. It works on a stock install, but if you've been using the system for any amount of time (adding patches, etc), the directory gets too big for a floppy - is that what's happening here, maybe?