i have the same issue here. Since latest versions users cant edit their posts. The option in the backend is set to YES i tried different settings but no luck. My users are complaining alot about it recently.
Thanks for your reply. The old behaviour and editing old own posts, is back.
Actually at the same moment that this issue arrised on our forum there was also a discussion started whether or not to delete a post. I see that there were some changes in the source concerning the deletion of posts.