variable defined in site-start.el not in .emacs or default.el

[Steinar Bang]

Platform: Intel Pentium M, debian sarge (testing/unstable)
          emacs21 21.3+1-8

I'm defining a variable for the site-lisp directory in the
site-start.el file:

(defvar company-site-lisp (file-name-directory (locate-library "site-start"))
  "Path to the Company site-lisp directory.
The default value here is the location of the site-start.el file.")

The company-site-lisp variable seems to be defined when used elsewhere
in site-start.el.  But it is reported to be undefined when I'm
attempting to use it in ~/.emacs and the default.el file.

Also it isn't found when doing `C-h v' after startup.

I thought this would be a globally defined variable?  The variables
I'm defining with defcustom seems to be working.

Am I doing something wrong?

Thanx!