Hmm. I can't watch digital high definition TV broadcasts either -- or rather, I can watch them, but with no sound or very distorted sound. This seems to be a known problem in Linux and it will no doubt be fixed. All other kinds of high resolution video work well, a prerequisite being that the video card can handle them.
So the question remains: are you talking about dvb or some other kind of video? And which video players have you tried?
(I've never started a poll so I can't tell you how to get rid of it.)