Ask PG: Qn on the 'More' link at the bottom of News.YC's home page

It changes with each page refresh now: from http://news.ycombinator.com/x?fnid=D5S0Tu4VK5 to http://news.ycombinator.com/x?fnid=ARW2OBvB6s... while pointing to posts 1-30. Any reason you are doing this? Similarly, the More link at the bottom of Page 2 also changes each time but still points to Posts 31-60. And so on.... I think that at one time, the URL used to be just /page2 or something easily guessable.