Possible bug in mobile export

[Simon Thum <simon.thum@gmx.de>]

Dear all,

I've set up my mobile sync, which worked fine in versions  6.3 - 7.7. 
Now I upgraded to 7.8 and when I fire up org-mobile-push I get:

Debugger entered--Lisp error: (void-variable org-agenda-filter)
   org-mobile-push()
   call-interactively(org-mobile-push nil nil)

The variable is not described, and I'm not very emacs-savy. However I 
managed to get to the lisp in question:

; org-mobile.el
;;;###autoload
(defun org-mobile-push ()
   "Push the current state of Org affairs to the WebDAV directory.
This will create the index file, copy all agenda files there, and also
create all custom agenda views, for upload to the mobile phone."
   (interactive)
   (let ((a-buffer (get-buffer org-agenda-buffer-name)))
     (let ((org-agenda-buffer-name "*SUMO*")
	  (org-agenda-filter org-agenda-filter)
	  (org-agenda-redo-command org-agenda-redo-command))


Should I configure org-agenda-filter, or is there something else I can do?

Cheers,

Simon