It's more of a "These, these, and these ATi cards are blacklisted and generally don't work well until we get better drivers" type thing. The card works fine, but there is no proper hardware rendering.

A new xorg.conf wont do a thing unfortunately.

EDIT: Also, that site is hilarious. They actually use glxgears as a serious benchmark tool. Hahaha.

But really, if I compile glxgears under some optimizations, I get 50fps, under others I get several thousand, with the same graphical output. Not a good tool to use for a benchmark.