diff -r 2e8c424dc638 Lib/test/test_sched.py
--- a/Lib/test/test_sched.py	Tue Oct 15 21:22:54 2013 +0300
+++ b/Lib/test/test_sched.py	Wed Oct 16 11:47:11 2013 +0300
@@ -41,7 +41,7 @@
             self._cond.notify_all()
 
 
-class TestCase(unittest.TestCase):
+class TestScheduler(unittest.TestCase):
 
     def test_enter(self):
         l = []
@@ -196,6 +196,35 @@
         scheduler.run(blocking=False)
         self.assertEqual(l, [])
 
+    def test_stable_run(self):
+        l = []
+        scheduler = sched.scheduler(time.time, time.sleep)
+        now = time.time()
+        ev1 = scheduler.enterabs(now + 0.01, 1, l.append, (1,))
+        ev2 = scheduler.enterabs(now + 0.01, 1, l.append, (2,))
+        ev3 = scheduler.enterabs(now + 0.01, 1, l.append, (3,))
+        scheduler.cancel(ev2)
+        scheduler.run()
+        self.assertEqual(l, [1, 3])
+
+    def test_stable_queue(self):
+        l = []
+        scheduler = sched.scheduler(time.time, time.sleep)
+        now = time.time()
+        ev1 = scheduler.enterabs(now + 0.01, 1, l.append, (1,))
+        ev2 = scheduler.enterabs(now + 0.01, 1, l.append, (2,))
+        ev3 = scheduler.enterabs(now + 0.01, 1, l.append, (3,))
+        events = scheduler.queue
+        self.assertEqual(events, [ev1, ev2, ev3])
+        self.assertIs(events[0], ev1)
+        self.assertIs(events[1], ev2)
+        self.assertIs(events[2], ev3)
+        scheduler.cancel(ev2)
+        events = scheduler.queue
+        self.assertEqual(events, [ev1, ev3])
+        self.assertIs(events[0], ev1)
+        self.assertIs(events[1], ev3)
+
 
 if __name__ == "__main__":
     unittest.main()