I've been using Danny Goodman's book as a reference material for my DHTML development work. Up until recently I had access to an HTML version of the book, provided by Safari. That format was pretty useful in looking up things, as they provided a hyperlinked index. Then they moved to a paper-like format which makes finding things much tougher. In the process they also dropped a few chapters. These chapters, unlike the bulk of the book, were not referenceware, but they were a very good coverage of the main topics in DHTML development. In fact, their coverage of events were the best I found in available literature. You can imagine my dismay when I discovered that exactly those chapters were dropped from this latest edition of the book.
The good thing though is that those chapters were made available online for free, as an online supplement reachable from the book's page in Oreilly's catalog.