Well, in my case the highlighting was returning nothing because of (my favorite acronym) PBCAK--
I don't store the text in the index, so I have to retrieve it separately (from a database) for the highlighting, and my database was not in sync with the index, so in a few cases the document in the index had been deleted from the database--thus a score, but no document text. But I guess my original question remains; under what conditions would the highlighter return nothing? Only if no terms matched? Donna
