B64 String Being Stripped From HttpService JSON Object Flex 4.0

I am trying to decode some b64 images obtained from a web service in my Flex application. The response of 开发者_如何转开发this web service is a basic JSON object, with a property (B64Image) that contains the encoded string. The service works fine from my regular browser, however the b64 string gets stripped. So the object the result handler gets has a null value for B64Image. Anyone see something wrong here?

EXPECTED OUTPUT

{
  "PropertyPhotos": [
    {
      "B64Image": "/9j/4AAQSkZJRgABAQEAYABgAAD....etc"
    }
  ]
}  

<s:HTTPService id="photoService"
                       url="http://localhost/dev/photohandler.ashx"
                       resultFormat="text"
                       result="photoService_resultHandler(event)"
                       fault="photoService_faultHandler(event)">
        </s:HTTPService>

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it's difficult to see, what could be wrong here, because such a few code...

what does the debugger say? does anything come back from the webservice? is the result or fault event thrown?