Num of returned ROWS

I'm using Postgres 8.0.3 and JDBC build 311 (tried 400 too) and using
executeUpdate to send the following command to DB:

set datestyle to ISO,DMY;
create table table1 as select F1, sum(F10) from table where F1 between
'1/1/2001' and '31/12/2004' group by F1;
select count(*) from table1

But the executeUpdate always return 0, even when the cont(*) return a
number other than 0.

Any ideas ?