Hatchet loves television

I have a big problem with my big dog and our big T.V.! Anytime Hatchet, a Rottie/Shep mix sees a dog or any kind of animal, crying baby, runner, bike rider go across the t.v screen he runs up to it. He barks and whines and cries! A few times he has even gone into a full reared up jump on the screen. I have tried distracting him with treats, putting him in "time out" in the kitchen, and none of that has worked. I now have to tether him to the end table by where i sit in the living room. I have been doing this for a month or so now and he will behave when tethered, but as soon as i take off the leash he runs to the tv! He gets praise and treats for being a good boy and laying still when he sees something of intrest, but when that darn "beggin strips" comercial comes on everything he knows goes out the window! We go on daily walks and have plenty of playtime in the yard but it dosent matter how tired he is he has to be right in front of the television! Can anyone help? Thanks!