10001 paypal internal error: timeout processing request Express Checkout

First of all, i dont have a Bussiness Account, so if that is the problem, just tell me, because is almost impossible to find where is the requeriment for Paypal Express Checkout in their official website.

My code for this API is:

$requestParams = array('METHOD' => $method,'VERSION' => $this -> _version,'USER' => $PayPalApiUsername,'PWD' => $PayPalApiPassword,'SIGNATURE' => $PayPalApiSignature);$request = array_merge($requestParams, $params);//$params is bringed from other php.$ch = curl_init();  curl_setopt($ch,CURLOPT_URL ,'https://api-3t.paypal.com/nvp');  curl_setopt($ch,CURLOPT_VERBOSE ,1);  curl_setopt($ch,CURLOPT_SSL_VERIFYPEER ,false);  curl_setopt($ch,CURLOPT_SSL_VERIFYHOST ,false);  curl_setopt($ch,CURLOPT_RETURNTRANSFER ,1);  curl_setopt($ch,CURLOPT_HTTPGET ,true);  curl_setopt($ch,CURLOPT_POSTFIELDS ,$request);$response = curl_exec($ch);

Then, until here is (i think) all right. But doing some checks this is what i sent with $request:

$request: array(16) {["METHOD"]=>string(18) "SetExpressCheckout"["VERSION"]=>string(4) "97.0"["USER"]=>string(27) "xxx_api1.example.com"["PWD"]=>string(16) "yyyyyyyyyyyyyyyy"["SIGNATURE"]=>string(56) "zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz"["RETURNURL"]=>string(50) "http%3A%2F%2Fwww.website.com%2Fcontinue.php"["CANCELURL"]=>string(53) "http%3A%2F%2Fwww.website.com%2Fpaypal%2Fcancel_url.php"["PAYMENTREQUEST_0_AMT"]=>string(5) "10.95"["PAYMENTREQUEST_0_CURRENCYCODE"]=>string(3) "EUR"["PAYMENTREQUEST_0_ITEMAMT"]=>string(5) "10.95"["PAYMENTREQUEST_0_SELLERPAYPALACCOUNTID"]=>string(24) "xxx%40example.com"["PAYMENTREQUEST_0_PAYMENTACTION"]=>string(4) "Sale"["L_PAYMENTREQUEST_0_NAME0"]=>string(17) "ProductA"["L_PAYMENTREQUEST_0_AMT0"]=>string(5) "10.95"["L_PAYMENTREQUEST_0_QTY0"]=>string(1) "1"["L_PAYMENTREQUEST_0_NUMBER0"]=>string(1) "1"}

And this is what i receive from Paypal:

$response: TIMESTAMP=2013%2d01%2d07T23%3a20%3a43ZCORRELATIONID=7a8130fb32e44ACK=FailureL_ERRORCODE0=10001L_SHORTMESSAGE0=Internal%20ErrorL_LONGMESSAGE0=Timeout%20processing%20request

Does anyone know what is happening here? Is this wrong? Is the premier Account the problem here?