I can’t set manage rights to outside-domain accounts in Google Calendar (GApps)

I can’t set manage rights to outside-domain accounts in Google Calendar (GApps)

I would like to add some users to be able to manage my GApps calendar. When the user is in my domain, there's no problem but when he's outside I can just set options like See all event details and See only free/busy (hide details). I need to set Make changes to events but it won't let me.
Why?
PS: in domain management in Calendar settings I have set sharing options like:

Outside Mydomain.net - set user ability
By default, calendars are not
  shared outside mydomain.net. Select the highest level of sharing that
  you want to allow for your users. 

Share all information, and outsiders can change calendars


Solutions/Answers:

Answer 1:

It works now. I don’t know where the error is but I think that it’s important to set Share all information, and outsiders can change calendars in Domain management Calendar settings and then you must wait until the change applies to google servers.

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