[AccessD] Query Too Complex

All,

I ran into something this week that I have never seen before.

I have a small Access 2007 reporting application that is pulling data from a Firebird database via ODBC.

One of the reports in the Access application has a Union query as its data source.

I have run multiple tests with the query it it works nicely.

I ran multiple tests of the report and it worked nicely at first.  In reviewing the report with one of our users, it was suggested that there was a field on the report that was not needed.

When I simply removed this one field from the report, I started receiving a "Query Too Complex" error.

If I put the field back in the report, the error goes away.  When I remove the field, the "Query Too Complex" error surfaces again.

I am very puzzled by this.  I can open the query by itself and it works fine.  When I try to open the report (when the field in question is removed), I receive the error.

I don't understand what happens behind the scenes when a report is opened.  Is the SQL in a query somehow changed when a report is opened?

I have now included the field on the report as "not visible" as a "work around", but I would really like to understand what is causing this strange situation.

Thanks,
Brad