PHP is only passing FILE name to my script

Question

I am working on building some AJAX video upload functionaliyy on my CMS, and ended up implementing the solution which was awarded the bounty here as it best suited my purposes (cross browser compatibility isn't an issue as I will only ever be managing my site via Chrome).

I've been experiencing some extremely strange behavior when I submit my form, when I var dump - the contents of my $_FILES array only includes the name parameter

The jQuery I use to submit to my upload file is as follows:

$('#confirm').click(function(){
var file = new FormData($('form')[0]);
$.ajax({
    url: './app/core/commands/upload.php',  
    type: 'POST',
    xhr: function() {  // Custom XMLHttpRequest
        var myXhr = $.ajaxSettings.xhr();
        if(myXhr.upload){ // Check if upload property exists
            myXhr.upload.addEventListener('progress',progressHandlingFunction, false); // For handling the progress of the upload
        }
        return myXhr;
    },
    //Ajax events
    success: function(data) {
        console.log(data);
    },
    error: function(data) {
        console.log(data);
    },
    // Form data

    data: file,
    //Options to tell jQuery not to process data or worry about content-type.
    cache: false,
    contentType: false,
    processData: false
});

});

Any ideas as to why my $_FILE array is empty?? I am baffled.