OK. I finally got it to work ... mabye it's my Otter Box!!!
OK. I'm on a Samsung SGH-I727, running Ice Cream Sandwich, 4.04 with Kernel version 3.08, build number IMM76D.UCLF6 here.
This is clearly a matter of getting the timing JUST RIGHT.
I tried it over and over, and could never get it to work.
But just now, I got it to work by experimenting with the timing, and now it seems to work repeatedly for me.
You have to
push both power and home at the same time.
What was messing me up was trying to consciously press power slightly ahead of home. They've got to both be pressed at exactly the same time for me. In fact, I can press the home button slightly before the power button and get it to work.
So what's been messing me up has been trying to press power first. That doesn't work at all for me.
For those having trouble: Press them both at exactly the same time, or as close to the same time as you can.
Maybe it's the clear screen protector in my OtterBox that slows the response of the "home" button slightly compared to how it would be if I was pressing directly on the phone's screen that causes this difference in perceived button press timing. I do know the phone's touch screen does operate better and has a nicer feel without the protective thingamajigger.
Are those of you who are having problems using protective screen covers and protective boxes? Even the power and volume buttons are a LOT harder to press with my box on the phone. Just a thought.
But I will say that the box has protected the phone for me in a number of spectacular drops and kicks down stairs and the like, so it's staying on the phone. :-[