jQuery File Upload : move_uploaded_file - error 3

I'm using the plugin from blueimp (https://github.com/blueimp/jQuery-File-Upload) to upload files.

I have a problem, when I'm uploading several files (like 20 pictures), the first 7 are uploaded correctly but after I get the PHP error (The uploaded file was only partially uploaded).

Is there something to configure with this plugin to avoid this problem ?

I set the plugin like that :

$('#upload').fileupload({
    // This element will accept file drag/drop uploading
    dropZone: $('#drop'),
    maxFileSize: 5000000,
    acceptFileTypes: /(\.|\/)(gif|jpe?g|png)$/i,
    // This function is called when a file is added to the queue;
    // either via the browse button, or via drag/drop:
    add: function(e, data) {

        var tpl = $('<li class="working"><input type="text" value="0" data-width="48" data-height="48"' +
                ' data-fgColor="#0788a5" data-readOnly="1" data-bgColor="#3e4043" /><p></p><span></span></li>');

        // Append the file name and file size
        tpl.find('p').text(data.files[0].name)
                .append('<i>' + formatFileSize(data.files[0].size) + '</i>');

        // Add the HTML to the UL element
        data.context = tpl.appendTo(ul);

        // Initialize the knob plugin
        tpl.find('input').knob();

        // Listen for clicks on the cancel icon
        tpl.find('span').click(function() {

            if (tpl.hasClass('working')) {
                jqXHR.abort();
            }

            tpl.fadeOut(function() {
                tpl.remove();
            });

        });

        // Automatically upload the file once it is added to the queue
        var jqXHR = data.submit();
    },
    progress: function(e, data) {

        // Calculate the completion percentage of the upload
        var progress = parseInt(data.loaded / data.total * 100, 10);

        // Update the hidden input field and trigger a change
        // so that the jQuery knob plugin knows to update the dial
        data.context.find('input').val(progress).change();

        if (progress == 100) {
            data.context.removeClass('working');
        }
    },
    fail: function(e, data) {
        // Something has gone wrong!
        data.context.addClass('error');
    }

});

Any ideas what could be the problem ?

Thanks for your help