Some of the videos may be restricted by the Youtube App. Some of the official sites may limit viewing and distribution, so it may not be your router settings at all. Unfortunately, I don't know what is and isn't restricted, but wanted to offer that as a possibility.
I have the Samsung BD-C6500 connected to my WIFI network at home, wireless 150N, linksys WRT120N router. My Netflix works great and Youtube but not with all the videos. Some of the official music video's found on Youtube, ex: Phil Collin's in the Air tonight, do not load and give me an error "Unable to receive URL information from movie site". Now I had read on another site that it might be my router security settings. I tried putting the IP address of the BD-C6500 in DMZ but that did not help.
Anyone else experience this problem and does anyone have any idea how to solve it?
Thank you for your help.