Thanks Alan - I'll try that.

The other possible culprit is a component for heavily-used prepared queries that uses CommitRetaining. It seems possible that 1 or 2 of these may be left open for a period of time. I've now made sure that it periodically issues a hard commit should it still be open. (Although I'm still mystified as if this was so it should show up in the gstat numbers - no?)
Tom

--- In firebird-support@yahoogroups.com, "Alan McDonald" <alan@...> wrote:
> I would do this:
> - Set sweep to 0 and do this manually
> - update to the latest 2.1.4 snapshot- I don't know what charset you are
> using but there is a memory loss issue fixed in 2.1.4 with regard to blob
> transliteration
>
> Alan