You are looking at the first edition.  I was using the second edition.  The first edition is riddled with typos, errors, bugs, etc.  One of those errors was the ncg error that has caused fmin_ncg to search in the wrong direction for the last ten years in scipy :)   Another erratum is on the line you mention.  This is erratum (8) in http://www.ece.northwestern.edu/~nocedal/book/2ndprint.pdf
I would be hesitant to use the first edition of the Nocedal and Wright book unless you have the list of errata handy.