As kimmie pointed out they are still there. They have moved so far back in time that they don't show up in the default view (last 30 days). Even though they carry a 1.1.90 date and appear as the first post in the thread. I think the system still sees and sorts them as the last post and even if others have a more current date. Kimmies method works as well as changing the defaults at the bottom of the page to include all (in the beginning).