Post request not working in IE9

[jwerre]

I've set up a cross domain POST request that is working in all browsers except IE9 (not worried later versions of IE). When the request is sent from IE9 Developer Tools show the correct request body was sent but when it shows up on the server side the request body is empty.

I should mention that I'm using a Backbone model to submit the request with Model.save() and I have the following ajax setup:

  $.ajaxSetup({
    cache: false,
    crossDomain: true,
    contentType: 'text/plain',
    dataType: 'json'
  });

On the server side I have the following headers:

"Access-Control-Allow-Origin", "*"
"Access-Control-Allow-Headers", "X-Requested-With, Content-Type"
"Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS"