To install Nvidias graphic-driver kernel-headers are needed, but they don't exist nowadays.
I am trying out several distros - mandrake 10.1, Suse 9.1 pro, Ubuntu (well, that's Debian so it shouldn't work), Mepis, WhiteBox .... None of them has these kernel headers, only in Slackware 10 could they be compiled.
I have the kernel source, at least Mandrake 10.1 has kernel.h in /boot, but that doesn't help, trying to download from Nvidia gives nothing.
So what am I to do? I need Nvidias driver for tv-out. (I could of course use Slackware but then Slack simply refuces to give me sound, I also find Slack's setup rather messy.)
(Could also be interresting to know why these headers aren't included any more when they obviously are important - this wasn't a problem with slightly older versions.)

Install the package called kernel-headers.

In Mandrake type in as root: urpmi kernel-headers

Forgot to mention that:
I tried it earlier, message "everything is already installed".
And isn't kernel-headers part of the sourcecode?

I'm having the same problem! I'm trying to install a rocket raid 1640 on fedora core2, and just cannot find any headers. I've tried:

yum -y search kernel-header-$(uname -r)

and that tells me no info is available. I've also tried

apt-get install kernel-headers-$(uname -r)

and again no luck . I would really like to see a solution for this if one exists. Sorry if it is not appropriate for me to join in on the discussion here, but I've been bangin my head on this for some time now.

these drivers need the headers from the source directory of the "current running kernel"
and that directory needs to be where the kernel was compiled originally..

if you are running some stock kernel then the package to install is "kernel-source" or something to that effect

there are some kernel interface headers in /usr/include/linux but they are headers to the kernel interface symbols in glibc not the includes to the current running kernel.

My problem was not the kernelheaders - problem was my head...
The Nvidia-drivers for kernel 2.4 and 2.6 have the same name, I tried to install the driver for 2.4 on a 2.6 system...