Fix for bug 307678 -- Fixing remaining MouseTrailer problems with dialogs.

r+sr=roc

widget/src/windows/nsWindow.cpp

@@ -909,6 +909,7 @@ nsWindow::~nsWindow()
 
   if (MouseTrailer::GetSingleton().GetMouseTrailerWindow() == this) {
     MouseTrailer::GetSingleton().DestroyTimer();
+    MouseTrailer::GetSingleton().SetMouseTrailerWindow(nsnull);
   }
 
   // If the widget was released without calling Destroy() then the native
@@ -1608,6 +1609,12 @@ NS_METHOD nsWindow::Destroy()
     nsBaseWidget::Destroy();
   }
 
+  // get rid of any mouse trailer references to self
+  if (MouseTrailer::GetSingleton().GetMouseTrailerWindow() == this) {
+      MouseTrailer::GetSingleton().DestroyTimer();
+      MouseTrailer::GetSingleton().SetMouseTrailerWindow(nsnull);
+  }
+
   // just to be safe. If we're going away and for some reason we're still
   // the rollup widget, rollup and turn off capture.
   if ( this == gRollupWidget ) {