Dear Ben,
to graphic mode) the screen is fully black. I tried several boot options like "fb=false" and/or "vga= ..." with several modes but this didn't helped.The correct option for disabling Kernel Mode Setting (KMS) would be 'nomodeset'.
I didn't know that! Thanks.
Btw., I verified by another fresh installation, that I only need the additional package "firmware-linux-nonfree" from non-free.[...] Radeon graphics chips seem to have become more and more dependent on GPU firmware. The driver will run without firmware available, and this works with older cards where firmware was only needed for 3D acceleration, but apparently this is not true for newer chips. Perhaps the driver should abort initialisation when firmware is not available for one of these.
Thanks for the explanation.I didn't had these problems with my previous installed kernel 2.6.32-5 from stable. Sorry, I forgot to mentioned that in my first message ...
Bye Ralf