The server committed a protocol violation

Hi can anybody tell me how to avoid this exception.My machine is running under proxy server,after setting the credentials and whenerver i am trying to get html content i am getting this exception. System.Net.WebException:The server committed a protocol violation. Se ction=ResponseStatusLine at System.Net.HttpWebRequest.GetResponse(). i had gone through one msdn document.In that document they have given that by setting these in machine.config we can resolve but still im getting please help me. . thanking you inadvance A.suneel