OK, I hope this solevs your problem, but you will need to have a standard XF86COnfig-4 file. I fou need one I can send you mine.
Mandrake is a great distribution, but I have encountered one anoying problem in 8.2 related to nvidia geforce4. Hopefull they will fix it in 9.0.
Anyway, the problem is this: there is a link called "X" in /usr/X11R6/bin that points to XF86_FBDev. This is wrong!!!! This caused my system to keep loading the standard vga drivers. To fix it remove the link by typing "rm X" (as root), and recreate it to point to XFree86 by typing (as root) "ln -s /usr/X11R6/bin/XFree86 X". All of this has to be typed from the /usr/X11R6/bin directory.
There's another X link in /etc/X11/ that also points to the wrong thing.
Try that and let me know.