Re: Making structure editable by registered users
And last, after trying Darkbee's suggestions, you could also try granting permissions to the homepage of the structure and it's child pages (tiki_p_edit_structures to the group you want).
It shouldn't be necessary (if you granted the permissions globally, and there are no local or categ perms), but just in case.... if this fixes the problem, then there is a bug in the code related to structures.
HTH