He's watching tv not gaming, whats he need a video card for?
I think rather the issue is the site not straming fast enough to keep up with playbeck. THats what I experience at least.
What I do is start a video and then once it starts playing I pause it and go off and do something for 5 - 10 minutes. When i get back I start watching again and usually dont have it 'stick' for the rest of the show.