I could state under what conditions it is possible to go on with the installation: If I switch to tty2, then the Select Category does appear on tty2, but I press e.g. Enter and switch back to tty1, the proecess is back in my hands. If I switch to tty3, then the whole thing is stuck and I get the keystrings of the keys pressed on tty3. BTW it is possible to switch ttys in all of the cases...