If you have implemented a pop-up menu (using Pop up menu command) for an object (such as a picture button), you may experience that the pop-up menu appears and disappears almost immediately after you click on the object. This behavior only occurs on the Macintosh. An easy solution is to make a copy of the picture button (Ctrl+D or Command+D) and change the type of new button to Invisible button. Place the Invisible button on top of the Picture button.