At the question: Is there a timeline for the 4.0.1 cdrom?
Klaus responded on the debian-knoppix mailing list:

Since both the 4.0.2 DVD and CD versions are basically finished, there
won't be a 4.0.1 CD version, but the upcoming 4.0.2 release instead.

The only thing I'm desperately waiting for, is unionfs to get into a
more stable state. At the moment, there are unacceptable instabilities
when overwriting existing files on a mounted unionfs directory multiple
times, resulting in Kernel Oopses after update-menus when a new debian
package is being installed, and cupsys frequently segfaulting because
the config file can't be rewritten. I would like to fix that, which is a
pure unionfs problem, before the release goes online.

If anybody would like to volunteer helping the unionfs team to find and
eliminate the bugs, please feel free to do so. Just get the current
unionfs snapshot from ftp://ftp.fsl.cs.sunysb.edu/pub/unionfs/snapshots/
and try to reproduce/debug the crashes reported in the bugtracker at
https://bugzilla.filesystems.org/ .

I have been trying to find the problem in unionfs, yet with no success,
during the past 2 weeks now.