This would occur in postNewUser() as there is no addGroup method. Changed things to use Auth::addUserToGroup() as is done elsewhere in the code.
The $user->save() had to be moved above this logic in order to avoid a constraint violation (need the user_id to exist before addUserToGroup can do its stuff).
User creation would fail when 'Superuser' was checked with the following: http://pastebin.com/hMfDrjuG
This would occur in postNewUser() as there is no addGroup method. Changed things to use Auth::addUserToGroup() as is done elsewhere in the code.
The $user->save() had to be moved above this logic in order to avoid a constraint violation (need the user_id to exist before addUserToGroup can do its stuff).