Rather than fight with two boot floppies, it is much easier to use Smart Boot Manager to boot the CD. Rather than make two floppies that will only boot this one live CD, you can make a SBM boot floppy that will boot any Live Linux CD, and actually any bootable CD at all.

If you have only 1 CD drive then booting Knoppix and burning CDs with it is a problem, unless you have a gig of RAM on the system (in which case you can use the toram cheat code and not need the CD in the drive when booting is done. But there are ways to deal with this. A simple one is to use a smaller Live Linux distribution, such as DSL. Since DSL is only 50 megs in size you can use the toram option on most systems and free up the CD drive. It has burning software also (although you may have to use the command line interface, not a GUI). And a trick I came up with just to see if it would work was to burn DSL to the first session of a multi-session CD (leave the disk open for additional sessions). I could then boot DSL rght from CD, leave it in the drive, and burn the files I wanted to the second session with the same CD in the drive. The resulting CD is no longer bootable (an unfortunate side affect of the way bootable CD's work), but it has up to 650 megs of recovered files on it. Of course, this is another good reason to boot with SBM rather than boot floppies, as the same SBM boot floppy will let you boot DSL too.

There is a fancier boot manager than Smart Boot Mamager called XOSL. I like it better. It too will let you boot from CD drives on systems that normally can't boot a CD quite right. But is is too large to fit on a floppy (has to be installed on the hard drive).

And SBM can be installed in the MBR rather than on a floppy. So you can just use a SBM boot floppy and not make any change to your system, or you can install SBM (or XOSL) to your MBR and not need to touch a floppy again, you system just comes up in a boot menu whenever you boot it. (In fact you could install SBM on a system that didn't even have a floppy drive.)