Log the queries

Hi everybody.
I was looking for a viable way to log ALL the queries (including
SELECT queries) that are executed onto a database. I need to log all
the queries onto disk (the logging program has to be run for a week or
maybe even more, so we can't use a visual logging).

We gave a try at two programs:

A. Interbase Performance Monitor. We experienced two problems. First
of all, we couldn't get "log onto disk" to work. Tables LOG$ are
effectively created in the database (to quickly see if it was working,
I set 1 second as interval), but they are empty. The second problem is
that not ALL the queries are logged, just the ones that are being
executed at the end of each quantum of time

B. IB LogManager. Doesn't log SELECT queries

Can you help us? Is there a way to solve these problems, or is there a
program that can do what we need?

Thanks in advance, Marco Bertini