I have the same problem with my 2nd Edition of the book. In fact, I once got a like-new copy at a library book sale just in case the old one wore out! Now I'm forced to use my coverless, broken spine 2nd Edition, as I got my like-new copy autographed by David Pogue (along with one of the many Missing Manuals).
I also have a copy of Que's "Upgrading and Repairing Macs" that has a cover made from duct tape. I was forced to do this nine years ago after six years of reading the book had worn it out.
I used to read both of these books almost daily. Both got counted for Book-It during second grade!!! (Keep in mind they each have 1000+ pages).
With the "Mac Bible", I got an ex-library book. This not only saved me a bundle (I got the 2nd, 3rd, and 4th editions for $1 each back when I was in middle school), it also gave me sturdier bindings. Those old library book sales allowed me to score some real gems in addition to the ones I mentioned--I got another copy of the Que book (brand new), Peter Norton and Jim Heid's "Inside the Apple Macintosh" (not too common of a book but quite good), and a practically new copy of DOS for Dummies--all for $1 each. Of course, I would have really been happy if I had found some Larry Pina titles or either of Arthur Naiman's non-Mac Bible books ("Macbook"--yes, the name was used on a Naiman book years before the computer of the same name came out--and "This is the Mac, It's Supposed to be Fun").