For anyone interested in the solution to this problem.
Using the authors' example .nib file as a starting point. In the window representing the nib file there is an object of type NSWindow representing the interface's main Window. Clicking on the triangle to the left to expand the contents of the Window object shows an object called Content View of type NSView. Clicking on the triangle to the left to expand the contents of the Content View shows the four objects added to the interface during the exercise: two Push Button objects of type NSButton, a text field of type NSTextField and a Bordered Scroll View of type NSScrollView. Clicking on each of these four objects and examining their attributes in the Size Inspector shows the "strut" and "spring (arrow)" settings of the Autosizing Mask. These settings are the same as depicted in steps 13 to 21 of pages 110 and 111 of the 2010 "Snow Leopard" version of the text.
But there is an additional mask autosizing control that appears in the Size Inspector of the Content View object. In the authors' example file, all four "struts" are in place and none of the "springs (arrows)" are selected. However if the bottom strut of this autosizing mask is removed the behavior mentioned in my original post occurs. Specifically, when pulling down on the resizing control, the two buttons, the small text field box and the top edge of the large multi-line text view box all migrate upwards past the menu bar while the bottom edge of the large text view box does not move down as the window's bottom edge is pulled down.
Last edited by mikem; July 22nd, 2010 at 10:50 PM.