another way to skin a cat is to try using a SQL select statement to drop the data you require from your existing two tables into either another table, or a cursor, and then choose your fields for your report from that new table or cursor.
an advantage of this is that you can immediately close your existing 2 tables after you execute your select statement, and before your report is run. this is especially beneficial if you expect users to preview a report, as your data tables are not open whilst they complete their preview.
good luck
Pete Bloomfield
Down Under