Problem with relationship API if all contacttypes

The relationship API returns an error if I try to establish a relation between an individual and an organization when the setup is All contacttypes.
I have set up a relationship type called Partner (see attachment) with All Contacttypes.

When I use the following code to add a relationship I get an error (Contact ID :3315 is not of contact type).
Code:
$params = array(
'contact_id_a' => 3315,
'contact_id_b' => 3314,
'relationship_type_id' => 30,
'start_date' => date("Y-m-d", strtotime("2010-01-14")),
'is_active' => 1);

// Call CiviCRM API functie to add relation:

$rel = & civicrm_relationship_create( $params );

/* write error if civicrm returns error */
print_r($rel);

The error disappears if I change the setup of the relationship to From Person To Organization. But I need this type as well between Organizations, and I assume this should work.