I have searchable .pdf-files in greek and english language. The folder search of windows xp lets me search for greek words only about 3 times. Then it finally only works with english words. "No results" shown for any greek word. With .doc-files it still works. (ifilter prob?)
If you kill the explorer.exe process and restart it again it works again, but same problem after a few searches.
This seems to be a reproducible bug because I have it on all XP-Computers I use.