Xorg 6.9 is in Debian Sid since 2005-12-29. Unfortunately the Linux ATI driver do not support it.
Here is my the error message I get in /var/log/Xorg.0.log:
[R200Setup] X version mismatch - detected X.org 220.127.116.11, required X.org 18.104.22.168
I read Mandriva 2006 have the same problem. I guess we have to wait…