Why to threads reappear on subsequent pages?

[Rockster]

I typically browse the forums by doing the following:

1. Select "What's New."
2. Beginning with page 1 of the results, I browse the titles. If a title interests me, I right-click the thread title and choose to open the thread in a new tab.
3. I repeat this process as I peruse all 10 pages of the "What's New" results. At this point I have a bunch of open tabs, each one holding a thread that interests me.
4. I read through each tab, closing the tab when I've finished reading and commenting on that thread.

I notice, though, that as I page through the What's New results that the tops of pages 2 through X contain threads that were on the previous page. What's up with that? It's obviously not a catastrophe but it's a but irksome and puzzling.

 

[p4594spa]

That's easy in between the time you bring a single page of threads and you hit next page, new posts have occurred which push the entries down on each page.