GeForce4 Ti4600 nVidia - grpahics settings for programs

I have the above mentioned graphics card, just installed Gentoo, and am quite unable to get anything that needs openGL to work. I have downloaded and successfully installed the graphics driver, and set x-server to use the settings, but I can not start up any of the games that need more than a text interface. I have tried armagetron, get error message: Display Driver "" - I am sure there is a config file somewhere that I could specify, but where can I find that? Every other program that needs more graphics gives me something similar to that message.

Audio: Is there any way to have Gentoo detect what type of sound card I have so I can get a driver?

Thanks

Did you specifically install the official Nvidia driver from the Nvidia website? Can you run glxgears?