display driver issues after kernel update

ive just updated my kernel and now X soes not work. I decided to then uninstall the driver according to the ¨known issues¨ section of the README and tried to install again. However now im getting this error:

ERROR: Unable to build the NVIDIA kernel module.
ERROR: Installation has failed. Please see the file
‘/var/log/nvidia-installer.log’ for details. You may find suggestions
on fixing installation problems in the README available on the Linux
driver download page at www.nvidia.com.

I also found this in the installer log file:

“[i] ERROR: Kernel configuration is invalid.”;
echo " include/linux/autoconf.h or include/config/auto.conf are mis
sing.";
echo " Run ‘make oldconfig && make prepare’ on kernel src to fix it
."; [/i]

any suggestions. All was working fine before i updated my kernel. Id built and run CUDA and OpenGL code on the machine without problems up until this point.

my kernel is as follows:

Linux 2.6.23.1-10.fc7

Please see:
http://www.nvnews.net/vbulletin/showthread.php?t=72490
http://www.nvnews.net/vbulletin/showthread.php?t=46678