title: FlexMouseEvent.MOUSE_DOWN_OUTSIDE works only for pop-up component?
body: <p>I have a component that extends UIComponent of Flex, I want to add it a FlexMouseEvent.MOUSE_DOWN_OUTSIDE listener but it does not works. that means I can not capture the event. But when I use PopUpManager to add this component, and then add a FlexMouseEvent.MOUSE_DOWN_OUTSIDE listener, it works fine. </p>
  
  <p>Is FlexMouseEvent.MOUSE_DOWN_OUTSIDE only works for pop-up components?</p>
  
  <p>Thanks for helping</p>