If you use an older tool with SAMBA 4 the special user accounts (Everyone for example) are still unrecognized.
You can reproduce this f. e. with the Server Manager for Domains when you try to create a share on the SAMBA host (altough the procedure doesn't work), but you see that the name resolution doesn't do it right.
I think we should work a bit on dcesrv_lsa_lookup_sid (maybe also dcesrv_lsa_authority_list).
Now properly fixed. Thanks!