Danke Lanzi,
hier stehts: " If you should own a ATI Radeon graphics accelerator, please use the failsafe option, when booting the Live-ISO. This option will add the cheatcodes radeon.modeset=0 xmodule=vesa to the Kernel bootline, so that you can boot to X. Before installing, on the Live-ISO, please install firmware-linux-nonfree."
mfg -hermann -