>
> My brother (who keeps the serves up to date) has produced some
> pictures of whatever the server is doing.
>
> They can be found here:
>
> http://download.microcom.dk/firebird/fb1.jpg

Virtual Size + Peak Private bytes = somewhere very close to 2^(32-1).
Could these have been at the same time?

Are you sure no-one has played with firebird.conf? A lot of the cache
settings etc refer to 'pages' rather than 'bytes' (each page can be up
to 16000 bytes), so it may be easy to accidentally overallocate some
of them if you don't realise that gotcha.

But as I advised a few days back (at least I think it was you), switch
to classic and this problem should dissappear.

http://download.microcom.dk/firebird/fb2.jpg

You are not making good use of your second CPU/Core, another reason to
consider classic.

Adam