I have never been able to get the like button to work properly.
When clicked only a small portion of the window that you type a comment in shows up.
I emailed their support from the Buffer.com website and I received and email back stating they will not support Digg Digg because it does not make them any money (which I do understand).
This error however makes the Digg Digg bar completely unusable for Facebook, and a waste of time to install.
If you know of another plugin that does the same thing. Use that instead.