I think when the page exceeds certain amount of postings, it's title is changed from the regular to the one having page number at the end. That way it says to the crawler the page's content has been changed (and it will be updated).
The hum around the SEO past months seems for me more and more insolvent, people are so much fallen into details (I don't mean you personally, Vishal
) they don't even deeply understand, instead of concentrating on the quality content instead, which will help them in rankings much much better.
I would mention the example of our minibb test
server, which has no useful content at all, all pages are marked with "NOINDEX" tag (except for the starting), and there is no useful content at all. Despite of this the site already has a PR=5. This proves that recommended tags and all other stuff doesn't affect nothing in reality. That is simply so much hassle that as usual, somebody just is making money on it.
Most probably I would say this time "thank you for the suggestion, but we won't change nothing regarding this case" - or at least I would like to hear other opinions, a lot of other opinions preferrably.