I have the next querys with FB RC2:

Q1:
select A.indice,A.nserv
from servico A
where A.ident_cp=13

Result:
Indice nserv
---------------
5 1
6 2
7 3
8 4
9 5

Q2:
select B.indice as Indice1,B.nserv as nserv1
from servico B
where B.ident_cp=395

Result:
Indice1 nserv1
---------------
1874 1
1875 2
1876 3
1877 4

Q3:
select A.indice,A.nserv,B.indice as Indice1,B.nserv as nserv1
from servico A
left outer join servico B on A.nserv=B.nserv
where A.ident_cp=13 and B.ident_cp=395

Result:
Indice nserv Indice1 nserv1
-----------------------------------
5 1 1874 1
6 2 1875 2
7 3 1876 3
8 4 1877 4

With this left join the correct result don´t will be:
Result:
Indice nserv Indice1 nserv1
-----------------------------------
5 1 1874 1
6 2 1875 2
7 3 1876 3
8 4 1877 4
9 5 null null

Thanks,

Luiz.