Yes. I use the following (possibly relevant) code definition, which sets my diary to agenda.org.
--8<---------------cut here---------------start------------->8---
(setq org-agenda-include-diary nil)
;; org-agenda
(setq org-agenda-diary-file "~/emacs/agenda.org"
org-special-ctrl-o nil
org-agenda-span 'day)
--8<---------------cut here---------------end--------------->8---
<e.fr...@ucl.ac.uk> writes:
> Have you defined org-agenda-diary-file?
