Damn Small Linux remastering problems

I'm remastering Damn Small Linux 0.4.10 (obviously), and it seemed to be going fine. I compressed the filesystem, and placed it in /mnt/hda5/KNOPPIX/KNOPPIX. Then I got boot.img off the DSL CD, and dd'd that to a floppy. I booted, and when the script ran "insmod cloop.o" it said it couldn't find the filesystem.
I thought it might be to do with using a floppy, so I made a proper CD ISO and burnt that - same error, and I wasted a CD.
Then I tried using Knoppix 3.3's boot.img, and that seemed fine, despite the modprobe errors because of the different kernel version.

So how can I use the proper DSL boot.img and get it to work?