I don't think PostgreSQL's sorting it wrong... here's the output of
Linux's sort utility:
edb82@linux:~> cat test.txt
GABRIEL ALEXANDRE DA SILVA MANICA
GABRIELA LETICIA BATISTA NUNES
GABRIEL ALCIDES KLIM PERONDI
GABRIELA JACOBY NOS
GABRIELA HELEDA DE SOUZA
edb82@linux:~> cat test.txt | sort
GABRIELA HELEDA DE SOUZA
GABRIELA JACOBY NOS
GABRIEL ALCIDES KLIM PERONDI
GABRIELA LETICIA BATISTA NUNES
GABRIEL ALEXANDRE DA SILVA MANICA
edb82@linux:~> psql -c "SELECT * FROM aluno ORDER BY nome" postgresid | nome
----+-----------------------------------36 | GABRIELA HELEDA DE SOUZA37 | GABRIELA JACOBY NOS38 | GABRIEL ALCIDES KLIM
PERONDI39| GABRIELA LETICIA BATISTA NUNES40 | GABRIEL ALEXANDRE DA SILVA MANICA
(5 rows)
--
Jonah H. Harris, Database Internals Architect
EnterpriseDB Corporation
732.331.1324