Thanks for your reply Sandra, the only firewall i'm using is the one in vista. I tried switching off that and downloading the guide but it still didn't work. For the first 2 months everthing worked great but for the past month it's been duff.
on 6/7/07 i recieved an update for media center and although I'm not sure exactly it was about that time when I started having trouble, it may have been a coincidense