Check out these sites for corrections.

Art Yarns 

http://www.artyarns.com/newsite/patterns_main.htm

Cast On magazine

http://www.tkga.com/cocorrections.shtm

Chris Bylsma Designs

http://www.chrisbylsmadesigns.com/oops.html

http://www.classiceliteyarns.com/pattern_errata.php

 Interweave Knits, Interweave Crochet, and Knitscene magazine corrections

Knitting and crochet books corrections 

http://www.keepitsimpledesigns.com/corrections.htm

http://www.knitnstyle.com/issues/corrections.shtml

http://www.knitonecrochettoo.com/errata.htm

http://www.knitwhits.com/errata.shtml

http://knittingpureandsimple.com/eratta.html

http://www.tradewindknits.com/errata.html

http://www.knittingfever.com/downloads.asp

http://www.sticksknits.com/errata/index.php

http://www.swallowhillcreations.com/errata.htm

http://www.tahkistacycharles.com/patterns/clarifications.pdf

http://www.catbordhi.com/Treasury.html

http://www.vermontfiberdesigns.com/corrections.php

http://www.vogueknitting.com/corrections.shtml

http://vogueknitting.com/books/clarifications.php