src/macosx/classes/sun/lwawt/LWMouseInfoPeer.java

*** 49,59 ****
      public boolean isWindowUnderMouse(Window w) {
          if (w == null) {
              return false;
          }
  
!         final Object windowPeer = AWTAccessor.getComponentAccessor().getPeer(w);
!         return LWWindowPeer.getWindowUnderCursor() == windowPeer;
      }
  
  }
  
--- 49,62 ----
      public boolean isWindowUnderMouse(Window w) {
          if (w == null) {
              return false;
          }
  
!         LWWindowPeer windowPeer = (LWWindowPeer)AWTAccessor.getComponentAccessor().getPeer(w);
!         // Most likely the cached window under cursor is correct and we do not need the native check.
!         // Also native check does not work for applets
!         return windowPeer == LWWindowPeer.getWindowUnderCursor() ||
!                 LWToolkit.getLWToolkit().getPlatformWindowUnderMouse() == windowPeer.getPlatformWindow();
      }
  
  }