I have managed to get Mandrake 9.2 working. I have been running with the NVIDIA driver for couple of days and so far it hasn't crashed.
Last time I tried to use a kernel newer than the one provided on the CD-ROMs. This time I reinstalled the system using the default 'enterprise' kernel that came 9.2. During installation the install program found a matching pre-compiled driver which it installed.
So far it seems better than before, but the output from glxgears is a bit low for a machince as new and fast as mine (details shown above).
12680 frames in 5.0 seconds = 2536.000 FPS
12891 frames in 5.0 seconds = 2578.200 FPS
12704 frames in 5.0 seconds = 2540.800 FPS
12755 frames in 5.0 seconds = 2551.000 FPS
12856 frames in 5.0 seconds = 2571.200 FPS
12777 frames in 5.0 seconds = 2555.400 FPS
X connection to :0.0 broken (explicit kill or server shutdown).
Lessons learned: If you are having trouble, go for a stock install first and don't get fancy with custom kernels. Another thing that may be of help to newer users:
When you first install Mandrake, choose version 4 of X and then choose the 'vesa' option. This should ensure that you will at least be able to get a basic version of X up and running no matter what. Once you do that make a copy of your XF86Config-4 file. I called my copy 'XF86Config-4.vesa'.
When you have things working with the vesa driver your X config file should be correct. Now you can go ahead and install and try the nvidia driver. All you have to do now is open the XF86Config-4 in your editor and change the line that has 'vesa' in it to 'nvidia'. I also made a copy of my nvidia config file which I called 'XF86Config-4.nvidia'. Depending on which X server I want to use, I copy the appropriate file to XF86Config-4.
Hope this helps.