You don't have to untar the files again after you've upgraded a kernel. I've been doing it for a year and had no problems... WHAT YOU DO is you type in:
and then type in:
Also, what you do to get the .tar.gz files working with *ANY* kernel is that you download the kernel-source rpm from redhat that matches your running kernel
Then you can just use the .tar.gz files and run make install in their directories.
So just do this:
(1) Install kernel-source rpm from red hat.
(2) go into Nvidia kernel directory and type in
(3) go into the Nvidia GLX directory and type in
(4) Edit your XF86Config-4 file (see the README in the GLX directory). Just make sure that it says Load "nvidia" instead of Load "nv" and that you take out the lines in the README.
(5) Reboot and enjoy, or come back and let us know the problem
Hope this helps. Please post any new problems, or let me know if something goes wrong.