ASP .NET and Web Services (SharePoint)

I am trying to use Sharepoint web services through ASP.NET. I can get to the main page and I was able to get the calendar data and display it. But somehow I can't get into the sub-sites. I am getting this error when I try to get into any sub-site or I still get the data on the SharePoint main page. Here's the error;
Exception of type 'Microsoft.SharePoint.SoapServer.SoapServerException' was thrown.

I have attached a screenshot of my Sharepoint with comments that what I am trying to accomplish.
Thanks much.

The Code:
Imports System
Imports System.IO
Imports System.Xml
Imports System.Xml.XmlNode

Partial Public Class _Default
    Inherits System.Web.UI.Page

    Private Function GetListNode() As XmlNode
        Dim RCPILists As New MCSLists.Lists
        RCPILists.Credentials = New System.Net.NetworkCredential("xxxxxx", _
    "xxxxx")
          Dim node As XmlNode = RCPILists.GetListItems("C & P issues", _
           String.Empty, Nothing, Nothing, String.Empty, Nothing, Nothing)
        Return node
    End Function


    Protected Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim node As XmlNode = GetListNode()
        Dim xr As New XmlTextReader(node.OuterXml, XmlNodeType.Element, Nothing)
        Dim ds As New DataSet
        ds.ReadXml(xr)
        ListBox1.DataSource = ds.Tables("row")
        ListBox1.DataTextField = "ows_Title"
        ListBox1.DataValueField = "ows_ID"
        ListBox1.DataBind()
    End Sub
End Class