XML : Using Volusion API to Import Order Data

I've been trying to use the Volusion API to import order data with no luck and support through Volusion is limited. I tend to lean towards a PHP solution, and their web site has this example for using the API for Import with php...

  <?php      //  Create the Xml to POST to the Webservice      $Xml_to_Send = "<?xml version=\"1.0\" encoding=\"utf-8\" ?>";      $Xml_to_Send .= "<Volusion_API>";      $Xml_to_Send .= "<!--";      $Xml_to_Send .= "    xml input file for \"\"";      $Xml_to_Send .= "-->";      $Xml_to_Send .= "</Volusion_API>";        //  Create the Header      $url = "https://www.xxxxxcomusa.com/net/WebService.aspx?Login=xxxxx@xxxxcomusa.com &EncryptedPassword=xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx&Import=Insert";      $header  = "POST".$url." HTTP/1.0 \r\n";      $header .= "MIME-Version: 1.0 \r\n";      $header .= "Content-type: text/xml; charset=utf-8 \r\n";      $header .= "Content-length: ".strlen($post_string)." \r\n";      $header .= "Content-transfer-encoding: text \r\n";      $header .= "Request-number: 1 \r\n";      $header .= "Document-type: Request \r\n";      $header .= "Interface-Version: Test 1.4 \r\n";      $header .= "Connection: close \r\n\r\n";      $header .= $Xml_to_Send;        //  Post and Return Xml      $ch = curl_init();      curl_setopt($ch, CURLOPT_URL,$url);      curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);      curl_setopt($ch, CURLOPT_TIMEOUT, 4);      curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $header);      $data = curl_exec($ch);        //  Check for Errors      if (curl_errno($ch)){          print curl_error($ch);      } else {         curl_close($ch);      }        //  Display the Xml Returned on the Browser      echo $data;  ?>    

I've edited this accordingly in order to get an order updated (used "Import=Update") but there is no 'data' output on the resulting page and the record does not get updated. I am able to get data returned from the api using a similar url so I know my encrypted password is correct. I think I also determined that the line that reads...

  $header  = "POST".$url." HTTP/1.0 \r\n";    

should read ...

     $header  = "POST ".$url." HTTP/1.0 \r\n";    

with a space after POST but I'm still not able to successfully update a record. I was hoping someone might have had success and can share more specifics on how you were able to import an update using the Volusion API (and hopefully PHP).