Ya seems to have been hacked or something :(. Let me look into it !! The parent site works and you can read the article there : http://shishirprasad.com/
Deduplication on the current stories was simple to implement as a first hack and that is why I did a prototype for it. But it is very easy to extend this idea to stories across time. All we need is to maintain an index of all hacker news stories and the same approach can very easily be implemented to prevent reposting old content too.
It will work for simple cases like https vs http or other cases of URL normalization but won't work for complex cases where they refer to the same content but with different title.