It does, at least for me. Consider this ARB example (recurring billing test). I got the following code from the SDK (php) after I created my test aurhorize.net account. It works as it created multiple recurring billing test purchases that I can view by logging into my test merchant account:
require_once 'anet_php_sdk/AuthorizeNet.php';
define("AUTHORIZENET_API_LOGIN_ID", "my_login_id_number");
define("AUTHORIZENET_TRANSACTION_KEY", "my_transaction_key");
$subscription = new AuthorizeNet_Subscription;
$subscription->name = "PHP Monthly Magazine";
$subscription->intervalLength = "1";
$subscription->intervalUnit = "months";
$subscription->startDate = "2011-07-28";
$subscription->totalOccurrences = "12";
$subscription->amount = "12.99";
$subscription->creditCardCardNumber = "6011000000000012";
$subscription->creditCardExpirationDate= "2018-10";
$subscription->creditCardCardCode = "123";
$subscription->billToFirstName = "Rasmus";
$subscription->billToLastName = "Doe";
// Create the subscription.
$request = new AuthorizeNetARB;
$response = $request->createSubscription($subscription);
$subscription_id = $response->getSubscriptionId();
Make sure you properly set things up in the config files. My config.php from the Anet_PHP_SDK which includes this arb example among others: (below is the code from my config.php) and that you have your test account API log in id and transaction key. They are ready to work instantly once you configure things properly.
require_once 'anet_php_sdk/AuthorizeNet.php';
$METHOD_TO_USE = "AIM";
// $METHOD_TO_USE = "DIRECT_POST"; // Uncomment this line to test DPM
define("AUTHORIZENET_API_LOGIN_ID","MY_LOGIN_ID"); // Add your API LOGIN ID
define("AUTHORIZENET_TRANSACTION_KEY","My_API_KEY"); // Add your API transaction key
define("AUTHORIZENET_SANDBOX",true); // Set to false to test against production
define("TEST_REQUEST", "FALSE"); // You may want to set to true if testing against production
// You only need to adjust the two variables below if testing DPM
define("AUTHORIZENET_MD5_SETTING",""); // Add your MD5 Setting.
$site_root = "http://YOURDOMAIN/samples/your_store/"; // Add the URL to your site
This honestly worked 'out of the box' for me during my testing.