Connection to WebService error

[Sergey Poberezovskiy]

Hi,

My VB.Net (1.1) application connects to ASP.Net (1.1) WebService that
resides on ISP Server. My client successfully runs this application from 4
out of 5 PCs. On that one PC I receive the following error whenever I call a
method of the service:

System.Net.WebException: The underlying connection was closed: An unexpected
error occurred on a send.

The procedure that fails is as follows:

Public Shared Function GetService() As MyService.MyService
Dim ws As MyService.MyService = New MyService.MyService
With ws
.CookieContainer = New CookieContainer
.Proxy = New System.Net.WebProxy
Dim cr As CredentialCache = New CredentialCache
.Proxy.Credentials = cr.DefaultCredentials
' The following call fails
.Authenticate(UserName, Password)
End With
Return ws
End Function

Any ideas why would the same code not work on one PC only - what I should
be looking for to rectify the error?

Any help is greatly appreciated - the client wants me to have it fixed
before the New Year...