[O] batch publish all, forcing. how?

[lbmlist]

I've been experimenting with:
emacs23 --batch -l ~/.emacs -f org-publish-all

to publish a total fresh version of my project, but it misses some files 
(an unchanging .css for example)

I suspect the optional force (defun org-publish-all (&optional force)...
might help, but I don't know lisp well enough to know how to send it 
force.

Can someone offer a howto?

Thanks in advance,

Louis