kde is somewhat a problem in debian as well as knoppix, but knoppix is more complicated since it uses stable, testing, and unstable packages. If you run into apt-get problems with knoppix try this apt-get command option:

apt-get -t unstable install package-name

the -t option forces apt-get to only use that one repository in this case unstable

allways do apt-get -s upgrade and apt-get -s dist-upgrade and simulate the upgrades and see what exacly will be done I usually pipe those commands to less so I can scroll through the listing. Apt-get upgrade will upgrade packages but not systgem dependencies like libraries etc. dist-upgrade upgrades everything. I just upgraded my kde 3.1.1 systems to kde 3.1.3 a couple of days ago, if I did a dist-upgrade a bunch of packages would have been removed, so I upgraded kde by itself by doing an apt-get install kdebase (or kdebase-bin) everything was OK here, but then I installed kdemultimedia and kde graphics and I ran into a problem, a file in kdemultimedia is in two packages so dpkg errors out. So I change directory to /var/cache/apt/archives and then use the following command:

dpkg -i --force overwrite kdemultimedia-kio-plugins_4%3a3.1.3-0woody1_i386.deb

dpkg had given me an error trying to install kdemultimedia-kio-plugins because a file was in it as well as kioslave.

Note: you have to use the full name with dpkg, I usually use dpkg from an xterminal so I can use my mouse to cut and paste.

HTH on a couple of your apt-get issues.

~rock