Embedded with FileResource is empty in the DOM

Hi all,

I try to embed a PDF in to my Vaadin App.
so I use following Code:

Resource res = new FileResource(Util.getPDF());

Embedded pdf = new Embedded("PDF-Embedded", res);
pdf.setAlternateText("No PDF-Plugin");

addComponent(pdf);

Everything is covered in a CSSLayout and the Util class returns a java.io.File
When I display the layout in the Browser I can see the caption. A also get a div that has the Style

<div aria-labelledby="gwt-uid-22" id="gwt-uid-23" class="v-embedded v-widget v-has-width v-has-height"></div>

but has no content nor reference to my PDF-File.

Anyone an Idea what I do wrong? I use embeded as it is not an Image, Flas nor an external Website…
Oh and I use Vaadin 7.2

Shouldn’t I have something like this in the DOM