>Thank you, Denis.
>
>1) Grouping is not involved in the query.
>2) The application was and is running exclusively under VFP 8.
>
>It just happens that I had used VFP 9 to add the fields, pack and reindex out of convenience. I mention VFP 9 *only* because I want to be rigorous in listing anything that could conceivably be involved.
>
>We are still stumped!

Did you remake index tags under VFP8?