I can't figure this out and would be very grateful for any assistance.

I have been running FB2.0 server on my development pc without problems
for many months and have just started having a problem connecting with
my app running on the same machine. I'm not aware of having made any
significant settings changes.

The FB server is definitely running and I can connect OK using IBexpert.

When I open my project in Delphi I get the following message:

ISC ERROR CODE:335544721
ISC ERROR MESSAGE:
Unable to complete network request to host "localhost".
Failed to establish a connection.
No connection could be made because the target machine actively
refused it.

The Firebird log shows:
HP_NX9420 (Client) Fri Jun 20 14:33:34 2008
INET/inet_error: connect errno = 10061

My Aliases.conf is:
inigo = E:\Borland Studio Projects\MLQGroup\Inigo\DB01.fdb

My app's ini file contains:
databasename = 'inigo'

I have tried restoring all my app files to an earlier version (which
worked ok). But I am still getting the problem so this suggests it is
not a problem with my app or its settings.

Any suggestions for how to fix this?

Many thanks
Mitch