title: Authentication Error when accessing Sharepoint list via web service
body: <p>I wrote a windows service a few months ago that would ping a Sharepoint list using _vti_bin/lists.asmx function GetListItemChanges.  It was working fine until a few weeks ago when my company upgraded our Sharepoint instance to SP1.<br>
  Now whenever my service attempts to access Sharepoint I receive an 401.1 authentication error:</p>
  
  <p>Error:</p>
  
  <blockquote>
    <p>You are not authorized to view this page <br> You do not have permission to
    view this directory or page using the credentials that you supplied. <br>Please
    try the following: Contact the Web
    site administrator if you believe you
    should be able to view this directory
    or page. <br>HTTP Error 401.1 -
    Unauthorized: Access is denied due to
    invalid credentials. <br>Internet
    Information Services (IIS)</p>
  </blockquote>
  
  <p>I have checked and my privileges on the site have not changed. here is the code In which I call the list:</p>
  
  <pre><code>Lists listsService = new Lists();
  listsService.Credentials = new NetworkCredential("UserName", "Password", "domain");
  Result = listsService.GetListItemChanges("List name", null, dTime.ToString(), null);
  </code></pre>
  
  <p>It has also been brought to my attention that basic authentication may have been disabled on our farm.  I don't believe I'm using that but I may be mistaken. </p>