I've installed a cheap ATI Radeon 9250 on my PC (running Debian Etch). I managed to install the ATI drivers (version 8.28.8) and kernel modules using
Flavio Stanchina's invaluable guide.
However, while I've got the fglrx driver working OK, including 3D acceleration, some applications aren't working. For example, Google Earth freezes during the splash screen, and fgl_glxgears only shows a glowing blue cube with no gears.
Investigations have suggested that this is a bug in later ATI drivers, and the only solution (at least for an old card like the 9250) is to roll back the driver to an earlier version (perhaps even 8.16 or earlier).
However, I'm not sure how to make those earlier drivers work with X.org 7.1, or even where to get hold of them (ATI's site doesn't go back that far). Any ideas? (Apart from Never To Buy An ATI Card Again - tell me about it; I was limited by budget and by only having PCI slots on my PC).