Molly Holzschlag writes Integrated Web Design: CSS Beyond the Retrofit at InformIT.com

An even greater concern is that many designers and developers have inaccurately but understandably blamed CSS and Web browsers for challenges with CSS. The problem at this point may really have more to do with the fact that important concepts in CSS are not explained to us in clear terms. As a result, what might appear to be a browser bug or a fault of CSS might simply be the result of the way CSS integrates with our HTML or XHTML documents, or how the concepts within CSS are resolving conflicts.