title: IE 7 prompts for username / password when URL contains an IP address but not when URL contains a hostname
body: <p>We have a web page that is configured for Integrated Windows Authentication under ISS.  When I access this page via its HostName (e.g. <a href="http://MyHost/mypage.htm" rel="nofollow noreferrer">http://MyHost/mypage.htm</a>) it works.  When I access this page via the IP address of the host (e.g. instead of MyHost, use MyHost's IP address in the URL), I'm prompted for a username &amp; password.  Can anyone explain why this is happening?</p>