Your issue is mostlikly with HDCP. What is HDCP? I'm glad you asked,
High-bandwidth Digital Content Protection (
HDCP) is a form of digital
copy protection developed by
Intel Corporation[1] to prevent copying of digital audio and video content as it travels across connections. These connections include popular ones like
DisplayPort (DP),
Digital Visual Interface (DVI), and
High-Definition Multimedia Interface (HDMI), as well as non-popular or now defunct connections like
Gigabit Video Interface (GVIF), and
Unified Display Interface (UDI). It is commonly, though incorrectly, referred to as
High-definition Copy Protection.
So in short you need to find the port on your tv that has the feature disabled. I have a Sony EX-500 and this is only disabled on HDMI port 1. All of the other HD ports have this feature. Basicly HDMI only exists because companys do not want you to make copies of movies. I guess they have never heard of DVD and Blu Ray Burners.

As for the svideo, the computer is correctly displaying what is being used. The round port which you are mostlikey using can be used for svideo and compent.
If you have any other questions just ask.