IMHO, the board search function is kinda crap. I use google to search the forums when I need to find something. Use the search string:
(your search goes here) site:www.dagorhir.com/forums/
You'll also get some hits from the old boards that won't want to render correctly, just delete the last semi-colon and everything after it from the address bar and refresh, it should render with the new formatting.