To complete this one man thread: the problem was me: typo in a join in the view.
Thanks to Dimitry Sibiryakov on the dev list for pointing this out.

Sorry for wasting everyone's time!

--- In firebird-support@yahoogroups.com, "realjimbeam" <realjimbeam@...> wrote:
>
> Seems there are no takers ;)
> I'll take it to the dev list (I've confirmed this error on 2.5RC3 as well); if I get no reply there I'll file a bug report...