I read somewhere (sorry to be so vague) that it is very important to power down the equipment at both ends before connecting or disconnecting HDMI cables. It sounded as though one might be risking damage to the equipment. Being a cautious sort (and having fried a few laptop motherboards over cable issues), and being aware that people who say "Heck, I do it all the time" may just be lucky, I have always followed this advice. But I'm wondering: Is it really necessary? Is there a problem with the HDMI design or spec or something? Are certain brands of equipment more susceptible to damage?