SQL Unions trough the ODBC driver

Hi all,

I'm wondering if someone has experiment problems using SQL statements with
UNIONS trough the ODBC driver. For example this SQL statement:

(SELECT DISTINCT compactes.numplec AS UnitId
FROM compactes)

UNION

(SELECT DISTINCT plecs.numplec AS UnitID
FROM plecs)

If I execute this inside Access it works perfectly, but if I execute it from
and ASP web page trough the ODBC driver it doesn't work.

Do you have any idea what is going on?

Thanks in advance.

Javier.