$.ajax({ beforeSend: function(xhr) { xhr.setRequestHeader(\'Authorization\', \"Basic YWRtaW46YWRtaW4=\"); }, url: \"https://test.com/incident.do
You say that you know its valid. Can you funnel it into the parseJSON function and see if you have any luck with that?
$.parseJSON(str_json);
Note: You haven't mentioned which version of jQuery you're using. This method is available only in jQuery 1.4.1 and above.