said by cypherstream:bicker is right.
For the most part, if someone is having issues with their HD hookup, 9 times out of 10 they need the 5 wire hookup anyway. You don't want them posting here "Why don't I have any sound?" do you? I don't think they use an A/V receiver or route digital audio to one if they think 3 cables of Red, Yellow, and White are for HD.
The 5 wire cable package I posted looks exactly like the only type of cable Comcast provides with their HD boxes in our area. And if you want HDMI, your on your own for that one (at least when I was installed).
Comcast had HDMI/DVI cables here. Although I certainly didn't use it.
Even when I used the component connection, I always used the optical or coaxial output for audio. I've been using digital audio capable receivers since 1997.