I know it is not your fault but it makes the system
almost unusable anyway:

in 10.2 alpha 4, I could install the ATI driver
for the Radeon X1600 card that came with my
preconfigured system, and it worked (apart from 3D).

in 10.2 beta 1, I only get the 1024 resolution
"framebuffer graphics", running "aticonfig"
reports no error, but X doesn't start thereafter.

I attach X.err, Xorg.0.log and xorg.conf

I will also report this to ATI, but would be very grateful
for some workaround if possible.