HttpWebResponse takes too much time

some company sent me an example url of their service.
this url (link) is an http request that request an xml document response from their server.

when i click the http request link that was sent to me ,i get the response in the IE window ,in about 2 seconds.

but when i use this code in my project:

HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http:......the url that was sent to me");

HttpWebResponse response = (HttpWebResponse)request.GetResponse();

the response takes 30 seconds!!

why ?