Get all images from specific Facebook album with Graph API PHP SDK

Hi I'm trying to grab all pictures from a specific album (always the same hardcoded id). I'm using the Graph API PHP SDK from Facebook. This is my code:

<?php
require 'phpfiles/facebook.php';

    $facebook = new Facebook(array(
    'appId'  => 'aaaa',
    'secret' => 'bbbb',
    'cookie' => true
));

$user_profile = $facebook->api('/1881235503185/photos?access_token=cccc');
var_dump($user_profile);

The var_dump output:

array(1) { ["data"]=> array(0) { } }

• 1881235503185 is the id of MY album that is not restricted, it's open to everybody
• the access_token is the token I get from my application page for my fb id. I don't get oauth errors.
• I have the permissions (user_photos) and tryed to add a dozen of other permissions.
• When I try it with the Graph API Explorer it works to.

When I use the Javascript SDK it works fine...

FB.api('/1881235503185/photos?access_token=cccc', function(response) {
    alert(response.data[0].name);
});

Output: Diep in de put

Am I forgetting something?