Of course it is a duplicate. The software doesn't catch all of those; that's on purpose, to allow good stories multiple cracks at the bat (edit: i.e. multiple chances to get attention). We rely on users to search before posting and on moderators to bury the dupes that sneak through. User comments pointing out the duplication are helpful.
This isn't a perfect system but it's much better than being too strict about reposts. We're going to work on a more effective dupe detection system as soon as we can get to it.
Because it's not reddit (stop acting like it's reddit - the communities and conventions are quite different) and if you want to participate in a discussion, stay in the thread.
Did you come from /r/programming? There have been a few comment threads talking about hacker news recently.
You're making excuses for poor UX in a way that makes you sound elitist. Not alerting you that you have replies is ridiculous. "Stay in the thread"? No, thanks, I'm not going to keep checking my comments for replies. Thankfully there's hnnotify.
It really does, but the anti-Javascript crowd here is very vocal and would likely inspire some sort of Digg-like exodus if the UI were ever brought into the 21st century.
