I don't recall if I changed it or the system defaulted it. Mine is currently set to "show all threads." I am not sure if this setting has anything to do with search feature either. It makes sense if it does though.

But still when I performed (key words) searches in the last couple weeks, I would see a funny phenomenon which I called "date jump" ( or FT Search Time Machine ). The results could be dated back as early as 1999. Sometimes it seems there's nothing happened between 2005 through 2007. I recall seeing search result with 5 or 7 threads, dated 2008, 2001, & 1999. Didn't know I could have used such rarely used "key" words that nobody had used in mid-2000s.

FWIW, this issue may fit better with either the Search Update thread or Search Problems.