I'm not sure exactly what happened to you, but I recently got my GF2 GTS 32mb working with Mandrake 8.1 without a hitch. Here's what I did. I got the .rpm's from NVIDIA, the GLX and the Kernel part (Make sure you download the 'nvchooser' executable script to tell which kernel version you need)

So I used:

NVIDIA_kernel-1.0-2313.mdk81up.i686.rpm
NVIDIA_GLX-1.0-2313.i386.rpm

And a copy of the readme file

NVIDIA Accelerated Linux Driver Set README & Installation Guide

Last Updated: $Date: 2001/11/26 $
Most Recent Driver: 1.0-2313
I opened the RPMs
NVIDIA_kernel-1.0-2313.mdk81up.i686.rpm
NVIDIA_GLX-1.0-2313.i386.rpm
with the x-windows Package Manager. Installed them both.

(I know this isn't quite that detailed, but I'm on Win98 right now)

I opened up the sample X config file under /usr/share/doc/NVIDIA_GLX-1.0/ and compared it to what I had, basically merging the information at the correct places, in other words, editing my (real X-config file) entries for the card, and adding the module area in the same way that it was shown in the example.

Then it was rebooting.

I'll post more tomorrow, do you want a copy of my X config file or anything?

(P.S.: I know it works, because I get a ton of frames per second in GLTron at high res)