Hi,
I wonder if it is advisable to always upgrade kernel headers while you are upgrading/installing the kernel itself?
Until now, I have never run "make headers_install" after I have upgraded the kernel manually and programs have compiled nicely anyway, but to maybe contradict that I discovered that there are accompanying kernel headers in the /testing/linux-2.6.30.5 directory (Slack 13.0), which I guess should be installed with that new kernel?
And also, should I always run "make headers_install" as a last step in kernel upgrading?

No. You should *never* do that.

With "that" I guess you mean "make headers_install"?
So running that after I compile a certain kernel (for example, 2.6.30.5) will not produce the same result as installing the kernel-header package for the same kernel?
Do the kernel headers in the 2.6.30.5 directory exist solely for the case that that kernel is the first you are installing (I really don't see how that could be accomplished during the installation process though), in order to have any headers at all to start with?

I think you're supposed to use the kernel headers that your glibc was compiled with.

Correct.