Lock Free Programming

I've been following this blog for a while:
http://bartoszmilewski.wordpress.com/

Generally a lot of good stuff there, but lately I've become interested in lock free programming and reasoning in a relaxed memory model.

Here's a taste:
http://bartoszmilewski.wordpress.com/2008/11/05/who-ordered-memory-fences-on-an-x86/

I find it interesting that the textbook linked on the page:
"The Art of MultiProcessor Programming"
Has this in the reader reviews:

The content is perfect and deserves 5 stars and I agree with the 5 stars comments,
but the code deserves the only 3 stars as there are a lot of flaws in it - the code even contradicts its description( both in the book and in the code downloaded from a site )...

This punctuates that the subject is so dense and counter-intuitive that even the experts in the field can't seem to get it right.