Since Mavericks each screen has its own status bar. This also means that an application running in the status bar (using NSStatusItem) theoretically has multiple NSStatusItem objects associated. In practice, although the user might see multiple "instances" of your NSStatusItem, it's just one (I've tested this). Now the following problem occurs when you're working with a custom view in your status icon: when the user clicks the status icon, I programmatically "highlight" it using the drawStatusBarBackgroundInRect method. The problem is that each "instance" of the status icon (one per screen) is highlighted although the user just clicked one. This behavior is different from a status icon without a custom view. Is there a way to implement this correctly?
For a good example just click on the Dropbox status icon when you're using multiple displays. You'll notice the selection of the icon on the other screen too.