Update:
Now it seems like there are problems with CUPS.
When I try to run the KDE print manager the following error occurs:

Code:
Connection to CUPS server failed. Check that the CUPS server is correctly installed and running. Error: connection refused
Someone suggested to do this as root: "/etc/init.d/cupsys start", so as to start the cups daemon. Also, this line was added at the end of /etc/init.d/bootmisc.sh
However, this did not have any effect.

Any ideas ?

P.S. localhost:631 will not work either: "Connection refused"