Receive processing request L_ERRORCODE0 = 10001 and timeout

I am trying to simulate a bogus parallel payment to two users using curl. I did everything according to the documentation, but the problem is that I get

Receive L_ERRORCODE0 = 10001 & Request to handle timeout

I do not know why.

My code looks like this:

<?php
   $data = array(
     'USER'=>urlencode('xxx'),
     'PWD'=>urlencode('xxxx'),
     'SIGNATURE'=>urlencode('xxxx'),
     'VERSION'=>urlencode('86.0'),
     'METHOD'=>urlencode('SetExpressCheckout'),
     'RETURNURL'=>urlencode('http://75.125.190.162:7132/sample/php_nvp_samples/myCheckout.php'),
     'CANCELURL'=>urlencode('http://75.125.190.162:7132/sample/php_nvp_samples/myCheckout.php'),
     'PAYMENTREQUEST_0_CURRENCYCODE'=>urlencode('USD'),
     'PAYMENTREQUEST_0_AMT'=>urlencode('300'),
     'PAYMENTREQUEST_0_ITEMAMT'=>urlencode('200'),
     'PAYMENTREQUEST_0_TAXAMT'=>urlencode('100'),
     'PAYMENTREQUEST_0_DESC'=>urlencode('Summer Vacation trip'),
     'PAYMENTREQUEST_0_SELLERPAYPALACCOUNTID'=>urlencode('himans_1331094418_biz@smartdatainc.net'),
     'PAYMENTREQUEST_0_PAYMENTACTION'=>urlencode('Order'),
     'PAYMENTREQUEST_0_PAYMENTREQUESTID'=>urlencode('CART26488-PAYMENT0'),
     'PAYMENTREQUEST_1_CURRENCYCODE'=>urlencode('USD'),
     'PAYMENTREQUEST_1_AMT'=>urlencode('100'),
     'PAYMENTREQUEST_1_ITEMAMT'=>urlencode('50'),
     'PAYMENTREQUEST_1_TAXAMT'=>urlencode('50'),
     'PAYMENTREQUEST_1_DESC'=>urlencode('Dancing class'),
     'PAYMENTREQUEST_1_SELLERPAYPALACCOUNTID'=>urlencode('himans_1320303266_biz@smartdatainc.net'),
     'PAYMENTREQUEST_1_PAYMENTACTION'=>urlencode('Order'),
     'PAYMENTREQUEST_1_PAYMENTREQUESTID'=>urlencode('CART26485-PAYMENT0')
  );

  $curl = curl_init('https://api-3t.sandbox.paypal.com/nvp');                       
        curl_setopt($curl,CURLOPT_RETURNTRANSFER ,1);                              
        curl_setopt($curl,CURLOPT_HTTPGET ,true);                                    
        curl_setopt($curl,CURLOPT_POSTFIELDS ,$data);              
   $response = curl_exec($curl);
   echo $response;
   exit;
   curl_close($curl);         
?>

      

        
        
        
      

    

Here is the vardump of the request:

array(15) { 
  ["USER"]=> string(43) "XXX"
  ["PWD"]=> string(10) "XXX"
  ["SIGNATURE"]=> string(56) "XXX"
  ["VERSION"]=> string(4) "56.0"
  ["METHOD"]=> string(18) "SetExpressCheckout"
  ["RETURNURL"]=> string(78)
    "http%3A%2F%2F75.125.190.162%3A7132%2Fsample%2Fphp_nvp_samples%2FmyCheckout.php"
  ["CANCELURL"]=> string(78)
    "http%3A%2F%2F75.125.190.162%3A7132%2Fsample%2Fphp_nvp_samples%2FmyCheckout.php"
  ["PAYMENTREQUEST_0_CURRENCYCODE"]=> string(3) "USD"
  ["PAYMENTREQUEST_0_AMT"]=> string(3) "100"
  ["PAYMENTREQUEST_0_ITEMAMT"]=> string(2) "50"
  ["PAYMENTREQUEST_0_TAXAMT"]=> string(2) "20"
  ["PAYMENTREQUEST_0_DESC"]=> string(13) "Dancing class"
  ["PAYMENTREQUEST_0_SELLERPAYPALACCOUNTID"]=> string(21) "seller-136@paypal.com"
  ["PAYMENTREQUEST_0_PAYMENTACTION"]=> string(5) "Order"
  ["PAYMENTREQUEST_0_PAYMENTREQUESTID"]=> string(18) "CART26485-PAYMENT0"
} 

      

        
        
        
      

    

API credentials have been intentionally removed.

And here's the answer:

   TIMESTAMP=2012%2d03%2d06T09%3a29%3a41Z
  &CORRELATIONID=184b37b1fd85
  &ACK=Failure
  &L_ERRORCODE0=10001
  &L_SHORTMESSAGE0=Internal%20Error
  &L_LONGMESSAGE0=Timeout%20processing%20request