> I have post this question one month ago, but I get no reply,
> so I retry because it's critical for me...

The thing to try is dropping the SQL Monitor on the form and
tracing what is actually being sent to the server. If the
expected statement is being sent and a lock is appearing on
the row then its time to report it to Firebird.

If the statement being sent has added WITH LOCK then you will
need to sent a sample of the problem to Jason.

PS. You could also try it on an IB_SQL or an alternative
Firebird tool - as what you are trying to do does not need
appear to need any code to demonstrate.

--
Geoff Worboys
Telesis Computing