A while back when we were having a lot of trouble with the site getting bogged down and hanging up all the time, the tech folk modified the search feature to limit results to 10 pages, I think.
The old threads/posts are all there, but it's harder to pull them up via a broad search like that one than it used to be.
Improving the search feature, in general, is high on our list of desired improvements when we update the site, which I promise is still in the works, albeit slowly! I'll check in to see if there's any way we can increase the returned results when we're doing that.
It's annoying that we have to send you elsewhere to search our own site, but you can use a search engine like Google to run a search here as well. For example, you can't search for three-letter terms via our current search engine, so you can search for EPM references via Google by entering the following into their search engine:
If you're searching for a past old thread of yours, and it's not coming up when you click on the find threads by link in your profile, you can also use our advanced search feature to enter some sort of search term to refine the search a little, and then search by username.
Feel free to PM me for help if you're having trouble locating a past thread. It's probably there because we haven't had to prune as much as we used to, though we're probably due for a round!