SamyGO

What is your firmware? Is it VALDEUC?
Could you use some other programs?
I believe you could use Skype with it too...
You needed to add skype program into your TV.

Please read this topic.
Also you have to buy some pricey cams as I linked here.

Samsung claiming CY-STC1100 will work on LED C7000 TV. on this link

I send a confirmation about it and the confimed, here is the reply message: http://forum.samygo.tv/viewtopic.php?f= ... 105#p19105
I can't confirm this, but if Skype camera work on LED series, it needed to work on Plasma too since they using same firmware!
But plasma C7000 does not in compatibility list.

Here is the links to CY-STC1100...
Ebay US ~$125 - Amazon US $110.86
Ebay UK ~?70 - Amazon UK ~?102 (This one like joke!)

FreeTalk at the other hand, hard to find and more expensive one here and here just supports C7000 and C8000 LED TVs again...

Why your camera doesnit works? Probably because TV doesn't have driver for your one