Kyle,

If you don't explicitly commit or rollback every transaction you
create and explicitly close the database connection then you are
relying on Firebird to detect that the connection has gone. In this
case, isapi may well be holding the connection open. In other words,
or as far as Firebird is concerned, the connection is still active.

Anyway, it has been years since I have encountered that beast so
others may be better placed to advise you on the pitfalls.

Adam