$.ajax() + async: false + jsonp

$.ajax() + async: false + jsonp


I'm trying to call a url with async: false but I always receive an
exception.
This problem happen with both release 1.2.6 and 1.3.2.
Here is the snippet:
var html = $.ajax({
url: 'http://ajax.googleapis.com/ajax/services/
search/web?q=testquery&start=0&v=1.0&rsz=large',
dataType: "jsonp",
async: false,
success: function(data, textStatus) { }
}).responseText;
responseText always throw a null or not an object exception.
any help?