"Stephen J. Barr" <stevejb@uw.edu> writes:

> I am using org-mode 8.2.10 with helm. When I am adding tags to a
> headline, the first tag offers me completions of all possible tags in
> the file. However, if I go back later and add additional tags, I am
> not offered completion. How can I fix this?

I can confirm that this is not just a helm problem. There is a bug with
all completion backends with the the following *default* settings:

(setq org-use-fast-tag-selection 'auto) ;; provided that shortcuts are
                                        ;; defined in org-tag-alist
(setq org-fast-tag-selection-single-key nil)
(setq org-complete-tags-always-offer-all-agenda-tags nil)

Steps to replicate (without helm):

M-x org-set-tags
[Tab] Select via completion [Ret]
[Tab] Only the most recent tab appears [Ret]

The following patch should fix the problem.