I think they're "new posts" just because you haven't read them yet, I'm guessing clicking that takes you to a list of threads with page numbers up to the double digits? this is a way to keep the old threads from coming up:
-click "user cp" at the top of the screen
-in the menu on the left click "edit options"
-scroll down to the thread display options section
-in the "default thread age cut off" subsection select "show threads from last month" (or any other length of time you prefer) and that will keep threads over a month old from being displayed
don't worry, we were all new here at one point too