Dear Mikalai and Adam,

Thanks to both of you for your detailed and very helpful replies.

I have added GDS32.DLL to both the main and client computers'
SYSTEM32 directories, and now a little test program I wrote will
execute, but with limited success...
The test program allows me to type a string into an edit box, then
puts that string into the IB Database component's DatabaseName
property and tries to execute a query against it.
When I run the test program from the shared drive (C:\DATA) from
the main machine, all is well: it correctly reads my test database
table's rows and displays the results. This happens both when I enter
the direct path/filename as well as when I enter the alias ("MAIN:T",
which I added to the alias.conf file).
However, when I work from the networked machine, and run the same
test program from the shared drive (drive Z), it fails (error 10061)
whether I use the alias or the direct path (here, "direct" means via
the Z drive). Before performing the connection, the program first
tries to find ("if FileExists") the file (if I give it a direct path,
not an alias), and in this case it reports successfully having found
the database file (which, indeed, does appear in the Z folder, as it
should).
So I'm at a loss as to why the database connection doesn't work
from the client machine, or what further to do or to test.
Any further help will be Greatly appreciated!

Reminder: XP Pro on all machines, peer-to-peer wireless-router
network, Firebird 1.5.4, Delphi 5 with IB components.

Thanks again,
-- Stan