title: SoapClient calls keep returning null
body: <p>I've been banging my head on this for awhile now, and I keep getting nowhere.</p>
  
  <pre><code>$client = new SoapClient($wsdl, array('trace' =&gt; 1));
  print_r($client-&gt;__getFunctions());
  $params-&gt;param1 = $cust;
  $params-&gt;param2 = "1f0de966909641061b729d383bd41bb2f0c3f4db";
  $response = $client-&gt;ValidateLicenseKey($params);
  print_r($params);
  print_r($response);
  echo "Last Request: ".$client-&gt;__getLastRequest();
  echo "Last Response: ".$client-&gt;__getLastResponse();
  </code></pre>
  
  <p>The output of that is as follows:</p>
  
  <pre><code>Array
  (
      [0] =&gt; ValidateLicenseKeyResponse ValidateLicenseKey(ValidateLicenseKey $parameters)
      [1] =&gt; CreateProviderResponse CreateProvider(CreateProvider $parameters)
      [2] =&gt; SetHardwareProfileResponse SetHardwareProfile(SetHardwareProfile $parameters)
      [3] =&gt; UpdateCurrentVersionResponse UpdateCurrentVersion(UpdateCurrentVersion $parameters)
      [4] =&gt; SoftwareUpdateAvailableResponse SoftwareUpdateAvailable(SoftwareUpdateAvailable $parameters)
      [5] =&gt; GetSoftwareUpdateResponse GetSoftwareUpdate(GetSoftwareUpdate $parameters)
  )
  stdClass Object
  (
      [param1] =&gt; satsys
      [param2] =&gt; 1f0de966909641061b729d383bd41bb2f0c3f4db
  )
  stdClass Object
  (
      [ValidateLicenseKeyResult] =&gt; 
  )
  Last Request: &lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns1="http://tempuri.org/"&gt;&lt;SOAP-ENV:Body&gt;&lt;ns1:ValidateLicenseKey/&gt;&lt;/SOAP-ENV:Body&gt;&lt;/SOAP-ENV:Envelope&gt;
  Last Response: &lt;s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"&gt;&lt;s:Body&gt;&lt;ValidateLicenseKeyResponse xmlns="http://tempuri.org/"&gt;&lt;ValidateLicenseKeyResult&gt;false&lt;/ValidateLicenseKeyResult&gt;&lt;/ValidateLicenseKeyResponse&gt;&lt;/s:Body&gt;&lt;/s:Envelope&gt;&lt;/pre&gt;
  </code></pre>
  
  <p>Why on earth print_r suggest that the return is null? This is just a simple call that checks to see whether a key is in the database or not. None of the other functions return results either. Can someone explain what's going wrong here?</p>