--- old/src/share/classes/com/sun/java/swing/plaf/windows/WindowsRootPaneUI.java	Mon Oct 29 18:49:00 2012
+++ new/src/share/classes/com/sun/java/swing/plaf/windows/WindowsRootPaneUI.java	Mon Oct 29 18:48:59 2012
@@ -31,6 +31,8 @@
 import java.awt.KeyEventPostProcessor;
 import java.awt.Window;
 import java.awt.Toolkit;
+
+import sun.awt.AWTAccessor;
 import sun.awt.SunToolkit;
 
 import java.awt.event.ActionEvent;
@@ -133,10 +135,15 @@
                 // window. If this time appears to be greater than the altRelease
                 // event time the event is skipped to avoid unexpected menu
                 // activation. See 7121442.
+                // Also we must ensure that original source of key event belongs
+                // to the same window object as winAncestor. See 8001633.
                 boolean skip = false;
                 Toolkit tk = Toolkit.getDefaultToolkit();
                 if (tk instanceof SunToolkit) {
-                    skip = ev.getWhen() <= ((SunToolkit)tk).getWindowDeactivationTime(winAncestor);
+                    Component originalSource = AWTAccessor.getKeyEventAccessor()
+                            .getOriginalSource(ev);
+                    skip = ev.getWhen() <= ((SunToolkit) tk).getWindowDeactivationTime(winAncestor)
+                            || SunToolkit.getContainingWindow(originalSource) != winAncestor;
                 }
 
                 if (menu != null && !skip) {