I mashed F12 with the site running (locally), and found:
Failed to load resource: the server responded with a status of 404 (Not Found) http://digg.com/img/badges/16x16-digg-guy.gif
So, this is why digg won't display - the gif is missing from its expected location.
Also, when I alter my LinkShare to specify the links I want explicitly (rather than selecting "All"), I see that GoogleBuzz is struck out, and marked as obsolete.