I have a second display attached to my MAC and this problem occurs when switching focus from one display to another. If MS-Word is running then when clicking on another application (either the window or choosing it from the pop-up bar at the bottom) the Word window will come to the top. The required window has to be found again using the pop-up bar, right-click etc for it to displace Word. Sometimes this operation has to be repeated a couple of times. Any way to stop this?