kernel-header installation question

[brownh@hartford-hwp.com (Haines Brown)]

I'm seeing to compile an inteface for the nVidia driver on a new
basic installation of debian 3.0r1. The nVida installation dialog says
the kernel headers are not found.

So I install the headers. The first time that went well, and the
second time:

       # aptitude install kernel-headers-2.4.18-bf2.4
       ...
       Sorry, kernel-headers-2.4.18-bf2.4 is already installed in the
       requested version (2.4.18-5). 

I find that my /usr/src/kernel-headers-2.4.18-bf2.4 directory only
holds a .config file and an include directory. I assume that what I
should see here is a file with an .h extension if the header is
actually installed.

I suspect that I'm making a simple (i.e., stupid) little mistake
somewhere. 

Haines Brown