When I visit the new page and upvote, it doesn't increment either even after upvoting then refreshing the page. But did it always do that? I don't think so - I think that, in the past, it would have incremented even without a refresh.

I wish we could view the new page at the same time and then both could upvote the same story to see what happens. It could be that all stories on new are shown with a score of "1" yet they really have a score of "0". If that was the case, the first vote just moves it from a fake "1" to an actual "1".