>Naomi gave you the answer, but just to jump in as well....anytime you have a pattern of two or more 1-many relationships and you're doing aggregations against multiple child tables, you must break it up into multiple subqueries, or multiple temporary result sets. Otherwise you'll get over-aggregation of the answers.

Thanks, yes, this is exactly what I did. I now have a query which is more easy to read and it does the job pretty good.