GetListitems not returning expected result - sharepoint

Question

I have created a windows application using list.asmx (getlistitems method) to download documents from a document library which is on another server. I am able to access document names, url, etc. When I use following code to download a file, it is returning html of the login page as content of each file that I am trying to download.
Any thoughts?
Dim spAuthentication As New Authentication()
spAuthentication.Url = authenticationWSAddress
spAuthentication.CookieContainer = New CookieContainer()
Dim spLists As New Lists()
spLists.Url = listWSAddress
'Try to login to SharePoint site with Form based authentication
Dim loginResult As LoginResult = spAuthentication.Login(userName, password)
Dim cookie As New Cookie()
'If login is successfull
If loginResult.ErrorCode = LoginErrorCode.NoError Then
'Get the cookie collection from the authenticatin web service
Dim cookies As CookieCollection = spAuthentication.CookieContainer.GetCookies(New Uri(spAuthentication.Url))
'Get the specific cookie which contains the security token
cookie = cookies(loginResult.CookieName)
'Initialize the cookie container of the list web service
spLists.CookieContainer = New CookieContainer()
'set the cookie of list web service to the authenticatio cookie
spLists.CookieContainer.Add(cookie)
'Dim responseNode As XmlNode = spLists.GetListCollection()
'response = responseNode.InnerXml
Dim query As String = "<mylistitems><Query><Where><Eq><FieldRef Name='FileDirRef' /><Value Type='Url'>DocLib/Property Documents/BELASERA AT FULTON (lax10027)/Master Meter Invoices</Value></Eq></Where></Query><QueryOptions><ViewAttributes Scope='RecursiveAll' IncludeRootFolder='False' /><IncludeAttachmentUrls>TRUE</IncludeAttachmentUrls><ViewFields><FieldRef Name='EncodedAbsUrl'/></ViewFields></QueryOptions></mylistitems>"
Dim doc As New XmlDocument()
doc.LoadXml(query)
Dim dt As DataTable = Nothing
Dim queryNode As XmlNode = doc.SelectSingleNode("//Query")
Dim viewNode As XmlNode = doc.SelectSingleNode("//ViewFields")
Dim optionNode As XmlNode = doc.SelectSingleNode("//QueryOptions")
Dim retNode As XmlNode = spLists.GetListItems("DocLib", String.Empty, queryNode, viewNode, String.Empty, optionNode, Nothing)
Dim ds As New DataSet()
Using sr As New StringReader(retNode.OuterXml)
ds.ReadXml(sr)
End Using
If ds.Tables("Row") IsNot Nothing AndAlso ds.Tables("Row").Rows.Count > 0 Then
dt = ds.Tables("Row").Copy()
For Each myrow As DataRow In dt.Rows
' myrow.Item(0) contains url of the document
If myrow.Item(0) IsNot Nothing AndAlso myrow.Item(0) <> "" Then
DownLoadAttachmentold(myrow.Item("ows_EncodedAbsUrl"), RemoveLookupID(myrow.Item("ows_FileLeafRef")))
End If
Next
End If
Public Shared Sub DownLoadAttachment(ByVal strURL As String, ByVal strFileName As String)
Dim myWebClient As New WebClient()
Dim DestinationFolder As String = "C:\\DownLoads\\"
Form2.RTBStatus.AppendText("Downloading File " + strFileName + " from " + strURL + " .......")
' The DownloadFile() method downloads the Web resource and saves it into the current file-system folder.
myWebClient.DownloadFile(strURL, DestinationFolder + strFileName)
'Form2.RTBStatus.AppendText("Successfully Downloaded file ""{0}"" from ""{1}""", "C:\\DownLoads\\" + strFileName, strURL)
Form2.RTBStatus.AppendText((ControlChars.Cr + "Downloaded file saved in the following file system folder:" + ControlChars.Cr + ControlChars.Tab + DestinationFolder))
End Sub

Answer 1

DownloadAttachment also needs to make (forms-based) authenticated HTTP requests.
An example in C# below:
request = (HttpWebRequest)WebRequest.Create(strURL);
request.Credentials = System.Net.CredentialCache.DefaultCredentials;//adapt for your FBA
request.AllowWriteStreamBuffering = false;
response = (HttpWebResponse)request.GetResponse();
Stream s = response.GetResponseStream();
FileStream fs = new FileStream(#"C:\DownLoads\"+strFileName, FileMode.Create);