[O] Debug (ox-odt): No OpenDocument schema files installed

[Melleus]

I'm trying to set up the odt exporter which is disabled by default.
After loading the exporter with:
      (require 'ox-odt)
I got the message about missing files.
I inspected the org-odt-data-dir and found that it points to
non-existant directory. So I did:
      (setq org-odt-data-dir "/usr/share/emacs/24.3/etc/org")
(the directory with the proper xml files) before loading the ox-odt
library. The result did not changed. I still got the message about
missing files.

I use emacs-24.3.1 and org-mode-8.2.7b from Debian repositories.

What am I doing wrong? (Or is it disabled by default because it's broken?)

Thanks ahead.