Timeout waiting for an answer in TCPClient

[QDL]

Hello everyone,

I have an ASPNET app which connects using a TCPClient to a Windows Service
and exchanges some data. I have installed this app many times on different
production boxes without problems.

On one particular Windows 2003, the ASPNET app gives me this error (actually
it is logged on a personal text log file):

"System.IO.IOException: Unable to read data from the transport
connection. ---System.Net.Sockets.SocketException: A connection attempt
failed because the connected party did not properly respond after a period
of time, or established connection failed because connected host has failed
to respond"

This happens after the connection has been established. (Client.connect)

The app still works because I have put up a loop which retries after waiting
half a sec. But they (users) complain it is to slow (15-20 seconds after
click). I tried increasing RXTimeout but to no avail.

The very same routines work ok if called from a WindowsForms app, so the
problem must be in ASPNET or, better IIS... Users say it started to have
this problem since a couple of months, without anyone installing anything...
Very, very weird.

I do not have access to the 2003 box, but I think it might miss latest
patches or even be without SP1...

Thanx in advance
Paolo