The CAPI functions to return or set the size of a top level interface (for example
capi:top-level-interface-geometry
) no longer include the interface toolbar in that size on the native Mac OS X GUI. This has been changed because the toolbar can be resized (or hidden completely) independently of the rest of the window, so including the toolbar's size leads to unrepeatable calculations.
LispWorks Release Notes and Installation Guide - 23 Dec 2011