James Jenner wrote on 04/10/11 22:55:
... The problem is that if you have a window selected that is not the image window, you loose the global menu, because the global menu is tied to the main window of the Gimp. ...
That is a bug, not a design flaw. <http://launchpad.net/bugs/646029>Once that bug is fixed, the global menu will work much better for Gimp than in-window menus did.
-- mpt