Using Firefox Firebug we checked the performance of one of our sites and noticed the following 2 404 (not found) errors:
First error: We integrated the CSS for tubepress into our standard style.css and as per the documentation were under the impression that the use of CSS by tubepress was deprecated.
Second error: We checked and we do not have an IMG directory under the DEFAULT directory in the tubepress plugin directory. So we don't know why it is searching for the .png file there.
The code in the header for this site is
<link rel="stylesheet" href="<?php bloginfo('stylesheet_url'); ?>" type="text/css" media="screen" />
we are using the latest version of tubepress.