The menu icon should act as a menu, not a button. Currently, when you click it, it shows or hides the menu bar. That's a fine feature, but that's the domain of an NSButton, not an NSMenu. It makes it confusing as to the purpose of the Tweetie icon menu. Every time I click it I expect to see a menu of options, but instead my tweet view disappears. That feature should be implemented in a way more consistent with the OS X user experience.