I don't know why Apple did this, but they made it so that if you try to output video to your TV with an A/V cable , you have to have to use the red RCA plug for video. Normally, it's the yellow one. Maybe they just wanted the extra $20 for their cable.

Everyone probably knows about this already, but it's new to me. Anyway, thanks to this article which details everything very explicitly. 

And if you're still having problems making an iPod compatible video, check this out .