Troubles with PostgreSQL

[eluser]hrundel[/eluser]
Hi, all. I'm not long ago begin to use CodeIgniter, it's nice and light for understanding framework.
But when I face to some troubles when I try to work with postgresql.
I edited database.php as needed and when loading database library thereis no errors i.e. connecting and selecting database passed successfully, but such construction

Code:

$query = $this->db->query("SELECT * FROM some_table");
echo "<pre>";
var_dump($query);
echo "</pre>";

return empty result_array, although some_table not empty. I'm use latest version of codeigniter and version of postgresql sever is 8.0
Doe's enybody know reason of my trouble.
Thanks.