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

[Brian Charlie]

Dim Briggs As New Z_SCART_CREATE_SALES_ORDER
        Dim P1 As New Briggs_N_Stratton.Zvscartordhdrin
        Dim P2 As New Briggs_N_Stratton.Zvscartorditmin
        Dim P2arr(1) As Briggs_N_Stratton.Zvscartorditmin
        Dim P3 As New Briggs_N_Stratton.Zvscartorditmout
        Dim P3Arr(1) As Briggs_N_Stratton.Zvscartorditmout
        Dim P4 As New Briggs_N_Stratton.Zvscartordtxt
        Dim P4ARR(1) As Briggs_N_Stratton.Zvscartordtxt
        Dim p5 As New Briggs_N_Stratton.Zvscartordmsgs
        Dim p5Arr(1) As Briggs_N_Stratton.Zvscartordmsgs
        Dim P6 As New Briggs_N_Stratton.Zvscartordpar
        Dim P6arr(1) As Briggs_N_Stratton.Zvscartordpar
        Dim SO As New Briggs_N_Stratton.ZScartCreateSalesOrder01


        Briggs.Credentials = New System.Net.NetworkCredential("NXTUSER", "Password")

        SO.Action = "B"
        SO.Sender = "ARITPP"

        ''OrderHeaderIN''
        P1.Ordtype = P(1, 1)
        P1.Salesorg = P(1, 2)
        P1.Distrch = P(1, 3)
        P1.Divis = P(1, 4)
        P1.Ordcatg = P(1, 5)
        P1.Custpo = P(1, 6)
        P1.Custpotype = P(1, 7)
        P1.Custporef = P(1, 8)
        P1.Delvprio = P(1, 9)
        SO.OrderHeaderIn = P1

        ''OrderItemsIN
        P2.Itmnum = P(2, 1)
        P2.Matnumin = P(2, 2)
        P2.Qty = P(2, 3)
        P2.Delvdate = P(2, 4)
        P2arr(0) = P2
        SO.OrderItemsIn = P2arr

        'OrderitemsOut
        P3.Itmnum = P(3, 1)
        P3.Matnumin = P(3, 2)
        P3.Qty = P(3, 3)
        P3.Delvdate = P(3, 4)
        P3.Matnumout = P(3, 5)
        P3.Description = P(3, 6)
        P3.Itmlistprice = P(3, 7)
        P3.Itmnetval = P(3, 8)
        P3.Itmtax = P(3, 9)
        P3.Itmtotal = P(3, 10)
        P3Arr(0) = P3
        SO.OrderItemsOut = P3Arr

        ''OrderLtext
        P4.Textid = P(4, 1)
        P4.Langu = P(4, 2)
        P4.Textline = P(4, 3)
        P4.Textline = P(4, 4)
        P4ARR(0) = P4
        SO.OrderLtext = P4ARR

        ''ordermessage
        p5.Msgsrc = P(5, 1)
        p5.Msgtype = P(5, 2)
        p5.Msgid = P(5, 3)
        p5.Msgnum = P(5, 4)
        p5.Msgtext = P(5, 5)
        p5Arr(0) = p5
        SO.OrderMessages = p5Arr

        ''Order Partners
        'PT 1
        P6.Custrole = P(6, 1)
        P6.Custnum = P(6, 2)
        P6.Name1 = P(6, 3)
        P6.Street = P(6, 4)
        P6.Addr2 = P(6, 5)
        P6.City = P(6, 6)
        P6.Region = P(6, 7)
        P6.Zipcode = P(6, 8)
        P6.Country = P(6, 9)
        P6.Emailadr = P(6, 10)
        P6.Telnumber = P(6, 11)
        P6.Faxnumber = P(6, 12)
        'PT2
        P6.Custrole = P(7, 1)
        P6.Custnum = P(7, 2)
        P6.Name1 = P(7, 3)
        P6.Street = P(7, 4)
        P6.Addr2 = P(7, 5)
        P6.City = P(7, 6)
        P6.Region = P(7, 7)
        P6.Zipcode = P(7, 8)
        P6.Country = P(7, 9)
        P6.Emailadr = P(7, 10)
        P6.Telnumber = P(7, 11)
        P6.Faxnumber = P(7, 12)
        'Pt3
        P6.Custrole = P(8, 1)
        P6.Custnum = P(8, 2)
        P6.Name1 = P(8, 3)
        P6.Street = P(8, 4)
        P6.Addr2 = P(8, 5)
        P6.City = P(8, 6)
        P6.Region = P(8, 7)
        P6.Zipcode = P(8, 8)
        P6.Country = P(8, 9)
        P6.Emailadr = P(8, 10)
        P6.Telnumber = P(8, 11)
        P6.Faxnumber = P(8, 12)
        'Pt4
        P6.Custrole = P(9, 1)
        P6.Custnum = P(9, 2)
        P6.Name1 = P(9, 3)
        P6.Street = P(9, 4)
        P6.Addr2 = P(9, 5)
        P6.City = P(9, 6)
        P6.Region = P(9, 7)
        P6.Zipcode = P(9, 8)
        P6.Country = P(9, 9)
        P6.Emailadr = P(9, 10)
        P6.Telnumber = P(9, 11)
        P6.Faxnumber = P(9, 12)
        P6arr(0) = P6
        SO.OrderPartners = P6arr


        Dim res As Briggs_N_Stratton.ZScartCreateSalesOrder01Response = Briggs.ZScartCreateSalesOrder01(SO)

        Return res

I've created this above code for a WSDL, that accepts values and then gives a responce back.  The code it self throws no errors but when it goes to use the function:
    Public Function ZScartCreateSalesOrder01(<System.Xml.Serialization.XmlElementAttribute("ZScartCreateSalesOrder01", [Namespace]:="urn:sap-com:document:sap:soap:functions:mc-style")> ByVal ZScartCreateSalesOrder011 As ZScartCreateSalesOrder01) As <System.Xml.Serialization.XmlElementAttribute("ZScartCreateSalesOrder01Response", [Namespace]:="urn:sap-com:document:sap:soap:functions:mc-style")> ZScartCreateSalesOrder01Response
        Dim results() As Object = Me.Invoke("ZScartCreateSalesOrder01", New Object() {ZScartCreateSalesOrder011})
        Return CType(results(0), ZScartCreateSalesOrder01Response)
    End Function

It throws the following error:
An Unhandled exception of type 'system.net.webExceptions' occurend in system.dll

Additional information: The underlying connection was closed: Unabled to connect to the remote server.

I've read up that it could be a firewall / proxy issue and I've even seen fixes for Asp.net such as: http://geekswithblogs.net/ranganh/archive/2005/08/29/51474.aspx

But I can't figure out how to get them to work with VB .Net 2003..

Any Ideas?

**For testing purpose the correct password is in place.

Thanks in advance!