DisplayPort to HDMI not working correctly?

Macbook Pro 2012 (Non retina) OS X 10.9.2 Belkin DisplayPort to HDMI adapter

When connecting displayport to HDMI adapter to my new 65" Vizio Smart TV. However, when I make the displays dual (that is, side by side), when watching movie with VLC player, if i try to maximize the movie on the TV, it blacks out my screen on MBP making it unusable. When i very first tried it, it worked fine, i could watch a movie while using MBP, but now I can find no way to make it work. Also, if i maximize safari or firefox on TV, macbook screen can still be used, only when trying to watch movie will MBP screen black out and not work until movie is minimized will screen come back.

ANY help greatly appreciated.