Use of indexes

Hi all,

i have a litte problem using indexes with datatypes int and int8.

i have a table

test:
id1 int,
id2 int8

if have to indexes:

index_test_1:
--------+---------
id1 | integer
btree

index_test_2:
--------+--------
id2 | bigint
btree

If i do any explains i got the following:

db_nmkm3=# explain select * from test where id1=1;
Index Scan using index_test_1 on test (cost=0.00..3.01 rows=1 width=12)

db_nmkm3=# explain select * from test where id2=1;
Seq Scan on test (cost=0.00..20.55 rows=1 width=12)

db_nmkm3=# explain select * from test where id2=1::int8;
Index Scan using index_test_2 on test (cost=0.00..3.01 rows=1 width=12)

Can somebody explain me whats wrong with me or my indexes?

thanks in advance