I got a 9600 from my brother to replace a 9500 in a side machine. The 9600 runs any D3D based game no issue. Tested 3 hours of Bad Company2 on it and World of Warcraft.
But, if I try OpenGL, the system eventually reboots itself. No BSOD or logged error, just an instant reboot. Most OpenGL based games take a bit, but RuneScape in particular will cause a reboot on demand when you log in.
I tried several driver versions and made sure Java was up-to-date.