having problems with the NVidia Driver Package #6629 using Fedora Core 3... failure to initialize NVidia Kernel...
...this appears to be a pretty common problem and other faqs/forums have yet to find a solution...
the xorg.conf.log states these errors...

(EE) NVIDIA(0): Failed to initialize the NVIDIA kernel module!
(EE) NVIDIA(0): *** Aborting ***
(EE) Screen(s) found, but none have a usable configuration

i assure you the conf is okay... this installation works perfectly with Red Hat 9...

Did RedHat 9 use XFree86? While FC3 makes use of Xorg?
Your screen section appears to be your problem. Re-run xorgcfg or xorgconfig or xorgsetup and try setting up your screen section again.

I had the same problem in FC2. I fixed it by downloading the nvidia kernel module, using the wonderful apt-get.

Do you have the rivafb module loaded?

I have the same problem but it also says something like "you are running X, unload x and try again" and then my question... How tha' h*** do i unload X and what is is?

The X Server is the system on UNIX that provides your gore GUI (graphical) functionality. On FC3you will be using an X server called xorg.

To stop X, first log out of your KDE/GNOME session.
Next press Ctrl+Alt+F6, you wll get to a login. Enter root as the username, and your password. When you login type 'telinit 3', this will stop X for you.

You don't know how much you just may have helped me. Thanx.