Oracle 9i: comparison of DATEs

Why is it that a query which looks like this:

select * from akcizastopa
where sifra = '777' and datumod = to_date('20.06.2003', 'DD.MM.YYYY')

returns one row, while

update akcizastopa
set iznos = 5
where sifra = '777' and datumod = to_date('20.06.2003', 'DD.MM.YYYY')

doesn't update any rows?

Please note that the where clause is identical. The contents of the table were also identical at the times I ran the queries.

Thanks Received on Thu Aug 21 2003 - 07:32:48 CDT