I should start going through the books and tallying them up...
The one I am looking at right now is Monster Manual IV, where the ToC says that a list of monsters by ECL is on page 221. Page 221 however has a list of monsters by type, and some short blurbs about the designers. The list of Monsters by ECL is actually on page 204 (dispite having a crappy layout).
Other errors in the ToC include:
Monsters Ranked by Challenge Rating, pg 221 (should be 204)
Monsters by Type (and subtype), pg 220 (should be 221)
Glossary, pg 204 (should be 205)
Another book I have, I think it's Heros of Battle, tells you on page X to goto page X for more info on whatever it is.. the real pain in the butt with that error is that the actual "more info" section doesn't exist anywhere in the book, so you're kind of screwed. I think it had tro do with warships... maybe it was strongholds. When I am not planning a campaign, I'll actually start cataloging these. It's rather annoying.
Combine these editing issues they've had consistently for a few years with the lower and lower quality of material being published... I think we have the makings of a failing production line.