I started from a fresh install of Slackware 10.0. I downloaded and compiled a 2.6.9 kernel, and got everything working right(framebuffer, alsa, etc.), so I was pretty pleased. I installed the ATI drivers the normal way(rpm2tgz, make, make_install, modprobe fglrx, fglrxconfig), fired up X and everything seemed fine. fglrxinfo said I have a 9500 pro as opposed to a 9700 pro, but it's always done that. glxgears was pulling in the avverage 3000-3500 fps so I thought everything was fine.

However, when I tried to play any games, all hell broke loose. If the game would even start, It would be slow(like software acceleration, 2-3fps), and have screen artifacts and corruption all over, and usually crash, taking the X server with it. This happens in both native games(tuxracer) and games I tried via Cedega(CS, Quake III). I know if I roll back to a 2.6.7 kernel it will work, but I really don't want to do that, because ACPI interfered with my onboard sound, and made it to strange things. I've read elsewhere that the ATI drivers work fine with 2.6.9 kernel on other distros, so I dunno what's going on. Help?

have you mounted tmpfs?

tmpfs /dev/shm tmpfs defaults 0 0

Go here for full instructions:
http://ati.com/support/infobase/4687.html

I had the same problems, and this should be all you need.

This newest ATI driver does not work with XORG 6.8. Stay with XORG 6.7 for the time being.

I've heard elsewhere that ATI's driver will work with XORG 6.8 on the next release (or two) at least they're working on it.