For anyone trying to set up a 301 re-direct and want to do it the easiest way in IIS. You can simply create a 2nd site call it something like non-www-mysite and set it to be a redirect. Then change its host header to
http://mysite.com then go into your main site and change host header to
http://www.mysite.com 
Simple overall re-direct.
I got better grade reports on my site already