After a long time I finally upgraded my really nice running Ubuntu 8.something to Kubuntu 9.04.
The Installation went very smoothly, no problems.
After that I started the System for the first time (suprise) and everything looked ok.
Next step I installed the nvidia glx 180-drivers and everything went bad. After installing and restarting my X didn’t came up again.
Sucks.

The pretty easy solution was lspci and adding my graphic-cards id to the xorg.conf (/etc/X11/xorg.conf) in the driver-section.
BusID "PCI:xx:xx:xx"
That’s it.

The interesting part came up when I started Amarok to listen to some music. First install the MP3-support, everything ok so far. Play a sound file.

It plays. Sound? no!

And again the solution I came up with shortly before I’d like to throw my pc out of my window:
Open alsamixer, increase the volumes. Simple, eh? For some god damne reason the important control was not present within the kmixer and set to zero.

What a wonderful activity to spend the morning with.

I hope this may help somebody to prevent the stress I had.

Cheers