I had the exact same problem.
For current alpha users: the work-around is to patch /usr/src/fglrx-8.522/firegl_public.c (using debian patch). After that, run dpkg-reconfigure fglrx-kernel-source
I had the exact same problem.
For current alpha users: the work-around is to patch /usr/src/ fglrx-8. 522/firegl_ public. c (using debian patch). After that, run dpkg-reconfigure fglrx-kernel-source