Do other video sites work? YouTube? Do you have any ad blockers in place? Have you tried using another browser to see if it also occurs there? If you right click on the black area, do you get the Flash Player context menu?
I just gave the site a try using Chrome but videos displayed properly.
Yes all other video sites work, I have tried Internet explorer and firefox also but they don't play the videos there either. and when I right click the flash player the context menu comes up, I tried changing the video quality but it just remains black. I have something called spyware blaster it says it prevents ad/ tracking cookies and prevents the installation of active-x based spyware... I think this might be the problem?
What version of Flash do you have installed? What browser and OS are you using? What sites are you having problems with? Is it just NBC?
I'd suggest doing a clean install to make sure everything is reset.