pb when creating user type

hello
I try to create a type complex, i generate a complex.so and when to insert
one complex into a table i have some problems
please help me

CREATE FUNCTION complex_out(opaque)
RETURNS opaque
AS '/usr/local/pgsql/complex.so'
LANGUAGE 'c';
CREATE

CREATE TYPE complex (
internallength = 16,
input = complex_in,
output = complex_out
);
CREATE

CREATE TABLE test_complex (
a complex,
b complex
);
CREATE

INSERT INTO test_complex VALUES ('(1.0, 2.5)', '(4.2, 3.55 )');
ERROR: Can't find function complex_in in file /usr/local/pgsql/complex.so
ERROR: Can't find function complex_in in file /usr/local/pgsql/complex.so
INSERT INTO test_complex VALUES ('(33.0, 51.4)', '(100.42, 93.55)');
ERROR: Can't find function complex_in in file /usr/local/pgsql/complex.so
ERROR: Can't find function complex_in in file /usr/local/pgsql/complex.so