Strange. I'm able to just go into screen settings, change it to 16:9 and 1080i, and that's it. What happens when you try to do it? No picture? Does 480p work?

Also keep in mind that the game defaults to standard NTSC 480i every time you start it up. This is sort of a safety feature to prevent against having to delete your save file because of not having access to a 1080i television. It's saved my ass a few times so far when I forget to set the game back to standard video after playing on the huge HDTV in my apartment lounge. ;-)