Paypal Autoreturn no post or get data - variables

Question

I have the following working in Sandbox
*Return without Autoreturn, no PDT;
*Return with Autoreturn, with PDT;
*IPN works properly
What I want to use is Autoreturn without PDT but when that is set Autoreturn sends no Get or Post variables. I've also checked the various other posts on this subject and rm=2 is set. Any help appreciated
$API_Endpoint = "https://api-3t.sandbox.paypal.com/nvp";
$PAYPAL_URL = "https://www.sandbox.paypal.com/cgi-bin/webscr?";
$newpost['business']='xxxxxxxxxx';
$newpost['cancel_return']='http://localhost/cz/subscribe.php';
$newpost['return']='https://www.xxxxxxxx/paypal/success_test.php';
$newpost['cmd']='_donations'; //donation checkout
$newpost['lc']='US';
$newpost['rm']='2';
$newpost['cbt']='Click to Set Subscriber Status';
$newpost['currency_code']='USD';
$newpost['button_subtype']='services';
$newpost['no_note']='1';
$newpost['no_shipping']='2'; //shipping address required
$newpost['tax_rate']='0.000';
$newpost['bn']='xxxxxxxx_BuyNow_WPS_US';
$newpost['amount']=$prod[1];
$newpost['item_name']=' Subscription'; //product name

Answer 1

After a lot of testing what I found was Paypal Sandbox as of Sep 23 2013 on non-PAYPAL account transactions autoreturns using IPN format when using CMD=_xclick, however on CMD=_donation it sits there waiting until the user clicks the return to mysite button.
*When processing a Paypal account transaction with CMD=_donation, autoreturn using IPN format returns nothing.* Using CMD=_xclick and allowing it to return in ten seconds works, as does clicking "If you are not redirected within 10 seconds, click here."
I don't know if this behavior occurs in production, however it rivals the readability of the Paypal documentation for clarity and understanding.