Select For Update bug???

Hi, I'm encountered a problem with a select for update sentence with
postgresql.

If I use...:
begin transaction;
select * from employees
where status = 'A'
limit 1
for update;
...

The problem, in the previous sentence, is block every record on employees,
although we want one record, we want limit 1. The bug it seems the limit
1, because if I dispose the limit 1 line, only the return records are
blocked.

If I use:
begin transaction;
select * from employees
where (status = 1) and (id_employee = 123)
order by id_employee
for update;
...
it block every record on employees, although we want one record, we want
id_employee = 123. The bug it seems the order by line, because if I
dispose the order by line, only the return records are blocked.

Do you have an alternative way? Is this a bug? Any suggestion?

I'm using Delphi 6 with dbexpress, and the transaction was make with an
TSQLClientDataSet component after an TSQLConnection

Pablo Avilés Cisneros
Technology, ITS
Software Development Area
Technology, ITS
San José, Costa Rica
email: paviles(at)its(dot)co(dot)cr