I think that's the problem: Mandrake 9.1 is using a "bleeding edge" kernel which has been modified with Supermount, etc., and hopefully nVidia will update their driver to cope soon.
(I've read somewhere that Mandrake are not fussy about including the latest stuff if they think it is stable, and this applies to the Kernel which I think is 2.4-21).
Meanwhile I still have Windows 98SE to connect to the net. As far as Linux is concerned, I love playing with it, and it is fun watching the software catching up with Windows. It will nose in front in the not-to-distant future, by which time I hope I have solved all my problems!