I am using the 2.6.10 kernel too.
I tried something I read in another thread after doing some searching about using apt-get (I use kpackage because it suits me a bit better and I upgraded all the relevent bits for Nvidia kernel etc but still nothing,
Anything else anyone has to offere would be gratefully received.
I also sometimes used "glxgears" to get a framerate on previous disros. When I try it now it gives me this:
Xlib: extension "GLX" missing on display ":0.0".
Error: couldn't get an RGB, Double-buffered visual
Don't know what this means or if it is relevent but I thought I would include it