Digg’s smart button widget is not working after their recent move to the new platform.
If you have a Digg button on your blog or website that lets your visitors easily submit your content to the bookmarking website, Digg.com, and it’s no longer displaying properly, don’t worry because they are aware of the issue. I follow their Developer Blog and they have listed this as a known issue.
After doing just a bit of digging (no pun intended) into the code, I realized that the JavaScript file that the Digg Smart Button Widget is dependent upon has gone missing and only receives a “Http/1.1 Service Unavailable” error message. Once this file has been repaired, I assume that the Digg Smart Button will be live once again.
This is great news for me since I have added this Smart Button to the Empowered Theme‘s floating widget. So if you are currently running the WordPress Premium Theme for Empowered Blogs, than you may have noticed the Digg Button isn’t showing up but don’t worry because it will reappear once Digg fixes their issues.
Update: Digg.com has just published that this issue is now resolved.
Source: http://developers.digg.com/known_issues

Thank goodness for folks like you who take the time to post because it really helps others. I had just finished adding the Digg button — 2 versions — in a new WordPress blog with a couple hundreds pages and right before the client was due to sign off on the project the button stopped appearing. It is helpful to find confirmation of the problem, I looked and looked for info on this. Thanks Clifton.
With Digg’s most recent changes. Their API has been online and offline quite a bit. Hopefully they will be able to straighten things out soon. Thanks for the feedback.