Image inside a input type="image" isn't render

Image inside a input type="image" isn't render

Hey,

Why I can't see the image inside a input type="image" when this kind of buttons are render?, this is my input: 
<input type="image" style="width: 150px;" title="" alt="" src="/misc/phpThumb/phpThumb.php?src= http://farm2.static.flickr.com/1279/5182967962_f2ebd59919_o.jpg&amp;w=50&amp;h=50&amp;zc=2" data-role="button" data-theme="d" />

jQuery Mobile doesn't support those kind of elements? another question, how can I disable jQuery Mobile to not apply input classes to some input elements, like this input type="image" for example.

Thanks.