Well, I did try to do the actualizing of KDE, it downloaded ok, but presented me an error within the replacement process:
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Fehler traten auf beim Bearbeiten von:
/var/cache/apt/archives/kdepim-libs_4%3a3.1.2-1_i386.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)
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translation of the first line: "errors occured during the processing of:"
After that I was given back the command line...
I tried the proposed "apt-get -f install", but that wanted to remove the whole KDE!

I'm going to reboot my computer now, to see if everything still works ok...

EDIT: back again, seems like no harm is done