firewalls? port numbers? ancient curses cast upon my servers?

Hello All,
Hopefully someone has come across this...

I have the client side of my application installed in the US,
with the application and the database servers running in london.

The program language is C#, all built in .net, with the .net installer.
When the user in the US runs the program and it gets to the
import progress part (background processing occurring on London servers),
they are getting no feedback as to the progress of the import.
ie, nothing is being sent to the US from the london server.
But everything runs smooth the other way, ie, tables are written to
the sql db's in london etc... And I get data sending and receiving
here in london when i run the client app on my machine and send to
the servers here, so its some problem with the connection with the US....
firewalls? port numbers? ancient curses cast upon my servers?

Cheers mike

Is this using SQL Server Integration Services (the SQL Server 2005 replacement for DTS)?
(In any case, if the "import" part isn't giving feedback, you probably should investigate the "import" part, to see what it does, and revise it to give feedback -- it may be hard for anyone here to know what this "import" part is -- if you suspect a connection problem, network sniffing, or even simple use of sysinternals tcpview may be helpful.)