I'm having similar problems on a TNT2 and a GeForce2 MX200(???) with RH9. (one's at work, one's at home, both machines are reasonable different)
Everything works fine except that I've had to disable the screen savers because some work fine, but some crash X.
I'm able to ssh the box and kill X (sometimes).
Mmmm, it's probably worth noting that the upgrade from the last driver to this one seemed to help but that the problem still exisits.
Also, I've noticed that the screen saver that looks like tetris pieces fitting into various rectangular shapes seems to crash X everytime, but that it doesn't seem to do it straight away. We at least when I come in and X has crashed, this is the screensaver showing up on the monitor.