. I do wonder though about screen resolution though... I'm not sure just how this works but the tv would not be able to work with certain resolutions so perhaps the login screen is not a resolution that the tv likes although this is a guess ;-). Have you tried different drivers? I would try at least a couple of driver versions to see if the problem is corrected.. If you had it set as your primary then perhaps you would have the login screen show up on your tv. Perhaps you might want to try that first.
so I hope someone can actualy reply with something solid but I would think that the laptop will not recognize the t.v hooked up until the system has loaded the operating system. Is there a way to set the laptop to use another monitor as primary? or is this not possible? if so then set the t.v as primary and see if that makes a diff. I'm a bit curous though why is it important that you have the login screen on your t.v if everything else after it works fine?