Drop-down menus in Emacs.app 23 (Lion) only work after several clicks

I am using Emacs.app 23.3.1 on MacOS 10.7.1 (Lion). When I try to use the GUI drop-down menus, they will not appear unless I click on the menu several times. The top-level menu item (e.g., File, Edit, Options) will highlight to acknowledge the click, but the menu will not appear. I have seen this question, but no fix ever appeared. I am not using Synergy. It is开发者_StackOverflow obviously not the end of the world, but it is an annoyance. I would prefer not to use the text-only menubar system. This behavior does not appear in Aquamacs.