keep in mind that it's usualy better and faster to use site's internal search capability like "SITE find <string> or "SITE search <string>" or whatever ftpd might be using.
anyway, regarding ffxp's search. it seem to work fine for me. however you could be confused with the way it works. it's somewhat differnt from "regular" windows search function.
windows goes thru dirs one branch at a time. flashfxp scan sites one lvl at at ime. 1st it scan all dirs in root, then all dirs in 2nd lvl, then in 3rd lvl.
here's an example. you search for "divx". say you have 2 dirs in / "games" and "movies". ffxp 1st get list of dirs from "games", then get list of dirs from "movies". chances are some subdirs in "movies" will have a string "divx" so those dirs will be displayed in search result window. now you would expect to also see files here, but no. flashfxp now scan subdirs in "games", and eventualy subdirs in "movies" where it will hit some files w/ "divx" in them. so as you can see, i hope
, files from subdirs that have "divx" in it's name will not be displayed untill flashfxp start scanning next level.
this is might be why you are not seeing files right away.
i hope this make sense.