IE 11 CORS POST request does not get sent

Hi,

I have a CORS POST request using jQuery AJAX that works in FF and Chrome, but does not get initiated in IE 11 (unless I enable IE's "Allow data sources across domains" security setting). No errors are shown in the developer console, and the request does not appear in the network tab at all.

$.support.cors = true;
$.ajax({
    contentType: 'application/json',
    data: {
        foo: 'bar'
    },
    dataType: 'json',
    type: 'POST',
    url: 'https://different-domain.com/path/to/service',
    success: function (response) {
        //do something
    },
    error: function (xhr) {
        console.log(xhr);
    }
});

I've seen it suggested elsewhere that this behavior occurs when the domain is localhost or when using the file:// protocol, but neither of these is true in my case (both the origin and remote are live, globally accessible, webservers).

Any ideas?

Thanks,

Drew Gallant