jQuery Ajax cors IE10 not working

Question

I'm using jQuery to do a post request to a different domain. This works fine on FF, Chrome and IE7,8 and 9. I was not expecting not to work on IE10..any ideas? Here's the code

var url = "http://xxxxxxx/xxxx.php?";

jQuery.ajax({
    type: "POST",
    async: false,
    crossDomain: true,
    contentType: "application/json; charset=utf-8",
    url: url,
    dataType: "json",
    data: JSON.stringify(params),
    success: function (data) {
        callback.call(Test, data, optional);
    },
    error: function ( jqXHR,  textStatus,  errorThrown) {
        alert(textStatus + errorThrown);
    }
});

Answer 1

Maybe security zones in IE has something to do with it? https://msdn.microsoft.com/en-us/library/ms537505(VS.85).aspx#xdomain

Tldr; It is possible that IE will not allow CORS, if it uses Native XMLHTTP, and if the two domains are in certain different security zones.