I have exactly the same problem.
Kubuntu 6.10 with 7900Gt and 1.0-9629:
glxgears gives ~15Kfps.
Direct rendering yes.
Startting OpenGL game is same thing as you press ALT+CTRL+BACKSPACE
Kubuntu 6.10 with 7950GX2 and 1.0-9629:
glxgears gives ~15Kfps.
Direct rendering yes.
Startting OpenGL game is same thing as you press ALT+CTRL+BACKSPACE
And 1.0-9742 works with native opengl games, but have some errors in wine with opengl . BAD Draw GLX if i remember correctly.
Now my solution is to go back to working driver... 1.0-9625.