Inspired by Official nVidia Drivers 28.32, I checked if they have new Linux drivers. And they have, Linux driver 1.0-2802 has been out for a while.

Release Highlights for 1.0-2802:

* GeForce4 and Quadro4 Support
* OpenGL® 1.3 with NVIDIA extensions
* Improved IGP and mobile support
* Overlay support for Quadro products
* MPEG acceleration for GeForce4 MX
* Anisotropic filtering support

Yes, I got those.

Don't ask me why, I have NO IDEA, but I have to compile from source and THEN install the rpms as well before it works....

(And then of course editing /etc/X11/xf86config-4 )

Then it works a treat. I don't really play games under Linux but those XMMS visualisations run so much better.....

\For my machine, I get an error message saying that some module can't be loaded and then this cool 'No screens found' thingy...

I have explainet this to myself by thinking that the nVidia rpm-s are made for _very_ default installations. I suppose that if you have changed _anything_ in your kernel or maybe other installations, the install will fail.

Can it be some explicit version checking, so that if some version number doesn't match, the module will not be installed?

Has anyone done any research on this? I really don't have time to go through some Linux discussion groups.

Anyway, installing from source isn't that difficult and you you can be sure that the compiler will produce optimal code for your machine.

True, RPM packages for specific distributions mean those specific distributions with their default kernels. That's why I recommend downloading source files & compiling them. It should be quite simple, instructions are in NVIDIA_GLX README.
This version (2802) does version checking, it can be bypassed by editing nv_linux.h but generally it's not recommended. As the README file says, this version doesn't work with experimental/development kernels (such as 2.5.x).