I faced no difficulties watching TED videos with AVG 2013 installed and active. Could you please try disabling individual AVG components pinpointing the one seemingly responsible for blocking the video playback? Then, please provide us with an msinfo output for analysis.
Also, please try disabling other active security software, if you are using something else than AVG at the same time. Generally, running additional security software with active resident parts is not recommended as the software may be conflicting with each other.
I am working on a new Lenovo Thinkpad. Installed AVG (free 2013) yesterday. Noticed images were blocked on a blog site I was visiting for the first time, but didn't think much of it. Today, I can't access video content on TED. Is this and AVG issue? Help appreciated.