Proof-reading programming books

[riddlermarc]

Do the publishers actually proof-read before sending stuff out to print? I was checking out details for a book I'm looking at buying:

http://www.wrox.com/WileyCDA/WroxTitle/productCd-0764576100,descCd-view_errata.html

.. more than one in ten pages has some form of error

 

[PinkPig]

I'm sure they're fairly hard to proof-read properly - but I have to agree that computing books in general are often ridden with mistakes. Not only that, but the majority are generally poor even without their mistakes - the number of books "for beginners" I've read which basically have chapters and chapters listing out every specific of a language, with a few inane examples and superfluous "change the text on the message box"-style exercises is scary.