> I suspect that this is not a
> JayBird issue, but rather something related to Firebird running on
> Windows.

As a confirmation of this, here's an article from IBPhoenix:

http://ibphoenix.com/main.nfs?a=ibphoenix&l=;KNOWLEDGEBASE;ID='457'

Question:

I have a non interactive service running, that collects data via ftp
from another computer and INSERTs this into my database. Now I want to
automatically do a backup/restore. I generated a batch file that does
what I want. But if I call the batch with ShellExec gbak reports:
gbak: ERROR: unavailable database

Answer:

You should be able to do this if you use the loopback remote access
method to access the database. That is:
localhost:D:\\daten\\ppcdata_tr4\\ppc.gdb

The local access method uses a virtual window to communicate between
client (gbak) and server (ibserver). Thus ibserver and any service
that interacts with it must interact with the desktop in order to use
this virtual window.

If you use the remote access method, the client doesn't use this
virtual window.

Roman