Inconsistent webservice behaviour

[MB]

We seem to have the exact same problem as Jim Duncan describes in his
post:
http://groups.google.se/groups?hl=s...nection+was+closed%22&hl=sv&lr=&start=70&sa=N

From stack trace:
System.Net.Webexception: the underlying connection was
closed: Unable to connect to the remote server.
at System.Net.HttpWebRequest.CheckFinalStatus()
at System.Net.HttpWebRequest.EndGetRequestStream
(IAsyncResult asyncResult)
at System.Net.HttpWebRequest.GetRequestStream()
at
System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke
(String methodname, Object[] parameters)
at

The resolution in that thread (supplying the proper proxy
configuration settings to the .NET client) however does not seem to
apply in our case.

Our Environment:
Win2k
Proxy present
..NET Framework 1.1 (No SP1 at the moment)

Does SP1 or any other fix resolve this problem?