Load group item perspective before creating the Items
Currently, the perspective/creator of a group is loaded concurrently with the items. If the items are loaded before the creator, the perspective will be displayed wrongly (race condition).
Quote from @grote
If I remember correctly, it would be better to change things so the perspective for the messages is known before they are created and then it can be passed to the message constructor instead of dynamically changing the adapter. Since this code is shared with forums, it might not be a trivial change though.
(see !532 (closed) for the initial discussion)