> I don't have a solution but I do have a suggestion: try to make a
> local connection as Administrator, and/or as the user that owns the
> Firebird process (if it isn't Localsystem). That will at least give
> you some additional information:
>
> - If Admin can't connect either, the local protocol isn't functioning.

I can connect as Admin, so the local protocol is functioning.

> - If he (and/or the Fb process owner) can connect, it must have
> something to do with access rights (but access to what?)

That's exactly the question.
The reason why I asked, is that with Windows Vista and the UAP every
process runs as normal user. So I wanted to test the scenario on XP as
normal user. But so far I have no solution, how a normal user can
connect to a firebird database with the local protocol.

Regards

Guido