I have the nvidia drivers loaded and running glxgears yields very disappointing results. Comes in around 650-700fps. I also get the following message when glxgears is run: "Xlib: extension "XFree86-DRI" missing on display ":0.0"." Any suggestions?

Telling us about the rest of your hardware might be a good idea. Also it seems it's looking for the dri module which if memory serves is meant to be DISABLED under the nvidia driver. Edit your /etc/X11XF86Config(-4) file and make sure the Load "dri" line is commented out or simply not there in the "Module" section. I believe "GLcore" is also meant to be disabled and "glx" enabled. Although memory is a little hazy on those.

ya try this, in your /etc/X11/XF86config file, add this to the
Section "Device" ---put it under the Driver "nvidia"

Hardware is a MSI K7N2G-L mobo with 512mb ram and barton 2500+. All slots are empty. Doesn't get simpler than this. dri is not enabled in my XF86Config and glx is. I have nvidia cards in other systems so I have done the download source, re-compile kernel and compile driver drill many times. Going through the XFree86.log I noticed the following errors:
...
(==) RandR enabled
Symbol __glXActiveScreens from module /usr/X11R6/lib/modules/extensions/libdri.a is unresolved!
Symbol __glXActiveScreens from module /usr/X11R6/lib/modules/extensions/libdri.a is unresolved!
(II) Initializing built-in extension MIT-SHM
...

Looks like this is the culprit. Googling around led me no where. Any ideas on how to resolve this? Thanks

Have a look to see if there's a file called that. It might be trying to compile it's own version of the dri module and failing... That's all I can think of.

Updated to the latest 2135 kernel and 5328 nvidia drivers recompiled everything and it now works fine. Getting around 1475 fps in glxgears. Slower than my GF2 Ti which is around 1700. I would have thought that the 4400MX would be a bit faster. Anyways, the problems are gone and no errors or crashes when the glx screensaver pops up.