Sometimes Data is not Showing

[DonPramis]

Hi, Sometimes the data are not showing. for (page authority,dmoz rank) i need to re do the test/ then it will come up:

Here is my code:

	/* Get SEOmoz Data
	-------------------------------------------------- */
		public function getSeoMoz($domain, $accessid = "", $secret = "")
		{
			try
			{
				$access_id = (empty($accessid) ? $_SESSION['SEOMOZ_API_ACCESSID'] : $accessid);
				$secret_key = (empty($secret) ? $_SESSION['SEOMOZ_API_SECRETKEY'] : $secret);
                                $expires = time() + 5000;
				$stringToSign = $access_id."\n".$expires;
				$binarySignature = hash_hmac('sha1', $stringToSign, $secret_key, true);
				$urlSafeSignature = base64_encode($binarySignature);

			$callback_url = "http://lsapi.seomoz.com/linkscape/url-metrics/www." . $domain . "?";
				$data = array(
					'Cols'		=> '68719493120',
					'AccessID'	=> $access_id,
					'Expires'	       => $expires,
					'Signature'	=> $urlSafeSignature
				);

				$curl_response = $this->curl->get($callback_url . http_build_query($data, '', '&'));

				if ($curl_response->headers['Status-Code'] == "200") {
					$parse_response = json_decode($curl_response, true);
					$domain_authority = $parse_response['pda'];
                                        $mozrank = $parse_response['umrp'];

                    $response = array(
						'status' => 'success',
						'data' => array(
						'domain_authority' => (int)round($domain_authority),
                                                'mozrank' => (int)round($mozrank)
						)
					);
                                        } else {
                                                   $response = array(
						        'status' => 'error',
						           'msg' => 'SEOMoZ Response Error.'
					);
                                      }
			            }
			  catch (Exception $e)
			                              {
				                       $response = array(
					                     'status' => 'error',
					                        'msg' => $e->getMessage()
				                        );
			         }
			return $response;		
		}