Error: "The underlying connection was closed: Unable to connect to the remote server."

[TechNeck]

We have developed a Web Service with vb.net using VS 2003 on a Windows 2003
Server. The Test application that we developed is passing 6 parameters to
the Web Service, which used to work fine. All of a sudden we are receiving
the following error message and can't connect:

"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)"

The client that controls the box states that nothing changed over the
weekend, but I know how many times "nothing has changed" means "we only
applied a few updates and changed a few permissions, but nothing that would
affect you!"

Any help would be appreciated.

TechNeck