Shareaza 2.7.4.0 64bit, with options: General.Search.Log = FALSE and Interface.AutoComplete = FALSE when I search something in HOME tab it still remembers search history (bug didn't persist in previous versions), searching using Search tab works correctly - no history saved.
I think that option "Filter Non-Matching Files" should be disabled by default or even removed from Shareaza. Let's assume my friend shares Landscapes.jpg file in Wallpapers catalog, when I search for phrase "wallpapers" his client returns Landscapes.jpg file which is immediately filtered as "Non-Matching File". That option is even ineffective against spam, because spammers returns exactly what you have have searched for.