Hello, I'm a prospective polyphasic sleeper,and I feel I've just learned something from yours and Steve Pavlina's blog: what matters most in achieving polyphasic sleep is *why you want to do it*.
You will fail if you want to do this to be cool, or if you just want to be able to tell your friends.. because those things aren't important: you probably won't impress them anyway. And even if you did, will that really improve *your* quality of life?
You will also fail if you want to do this just to have more hours in the day to get things done, to write more code (or whatever it is you do), or to make more money. Because are those things really important? Will you really be happy? Will your quality of life *really* improve after you've gotten those things done? Will you really enjoy getting them done more so as a polyphasic sleeper than you would as a monophasic sleeper? What's so wrong with getting them done at the rate of 16 hours activity per day rather than 21 hours activity per day? Either way it's still 1 hour activity per waking hour, and that's all were concious for, so the rate doesn't really change as far as our perception goes.
The real reason (I think) for anyone to do this should be for the reason Steve Pavlina did it: for the experience alone, as a life changing event. "Life changing events" and "experiences" are the types of things that can actually improve our quality of life. And aparently, our bodies (actually our sub-conciouses) know the difference.
But can't you just get a large enough alarm clock and wake up anyway? that's all it is is waking up, right? Well, I'm sorry, but you are case in point that the answer is "no".
I'm not trying to be a downer here or to put you down or insult your efforts. Actually, I'm amazed by your determination and commitment, and having stuck with it for so long without making it all the way. That part is very impressive. I just think that you have the wrong motivation, and it could be the source of your difficulties.
So what I'm saying is that our subconsciouses are very strong, and the sleep deprivation you experience when you try to start a polyphasic sleep cycle is a very strong influence on your subconscious. The only conscious control you have over sleep is (for the most part) the time you set the alarm for. And I think you've shown us how readily a sleeping (subconscious) person can turn it off.
I realized this after reading your motivational letter to yourself, many posts back. It just seemed like you were really focused on impressing people.
Now of course, I could be totally wrong here, so don't get too mad at me ;)