The environment:
FoxPro tables linked into an Access 2000 (or 2003) database using Microsoft VFP ODBC driver 6.0.something.
Ran a simple select query on a single table. Group by a date field and sum the total paid column to get a total by month.

The Problem:
Ran the exact same query multiple times one immediately after another by 1st running the query, get the result, then switch back to query design view and ran it again without changing anything. Each time, the total is different. Sometimes by 10's, sometimes by 100's.

Anybody knows why?