Similar failure on AMD64 Windows8 3.6:

http://buildbot.python.org/all/builders/AMD64%20Windows8%203.6/builds/425/steps/test/logs/stdio

(...)
test_abort_and_reset (test.test_threading.BarrierTests) ... ok
test_action (test.test_threading.BarrierTests) ... ok
test_barrier (test.test_threading.BarrierTests) ... ok
test_barrier_10 (test.test_threading.BarrierTests) ... ok
test_default_timeout (test.test_threading.BarrierTests) ... Unhandled exception in thread started by <function Bunch.__init__.<locals>.task at 0x000000B21066D9B0>
Traceback (most recent call last):
  File "D:\buildarea\3.6.bolen-windows8\build\lib\test\lock_tests.py", line 38, in task
Unhandled exception in thread started by <function Bunch.__init__.<locals>.task at 0x000000B21066D9B0>
Traceback (most recent call last):
  File "D:\buildarea\3.6.bolen-windows8\build\lib\test\lock_tests.py", line 38, in task
Unhandled exception in thread started by <function Bunch.__init__.<locals>.task at 0x000000B21066D9B0>
Traceback (most recent call last):
  File "D:\buildarea\3.6.bolen-windows8\build\lib\test\lock_tests.py", line 38, in task
    f()
  File "D:\buildarea\3.6.bolen-windows8\build\lib\test\lock_tests.py", line 917, in f
    f()
  File "D:\buildarea\3.6.bolen-windows8\build\lib\test\lock_tests.py", line 917, in f
    f()
  File "D:\buildarea\3.6.bolen-windows8\build\lib\test\lock_tests.py", line 917, in f
    i = barrier.wait()
  File "D:\buildarea\3.6.bolen-windows8\build\lib\threading.py", line 612, in wait
Unhandled exception in thread started by <function Bunch.__init__.<locals>.task at 0x000000B21066D9B0>
Traceback (most recent call last):
  File "D:\buildarea\3.6.bolen-windows8\build\lib\test\lock_tests.py", line 38, in task
    i = barrier.wait()
  File "D:\buildarea\3.6.bolen-windows8\build\lib\threading.py", line 612, in wait
    self._wait(timeout)
  File "D:\buildarea\3.6.bolen-windows8\build\lib\threading.py", line 652, in _wait
    i = barrier.wait()
  File "D:\buildarea\3.6.bolen-windows8\build\lib\threading.py", line 612, in wait
    f()
  File "D:\buildarea\3.6.bolen-windows8\build\lib\test\lock_tests.py", line 917, in f
    self._wait(timeout)
  File "D:\buildarea\3.6.bolen-windows8\build\lib\threading.py", line 652, in _wait
    raise BrokenBarrierError
threading.BrokenBarrierError
    self._wait(timeout)
  File "D:\buildarea\3.6.bolen-windows8\build\lib\threading.py", line 652, in _wait
    i = barrier.wait()
  File "D:\buildarea\3.6.bolen-windows8\build\lib\threading.py", line 603, in wait
ERROR
test_reset (test.test_threading.BarrierTests) ...     raise BrokenBarrierError
threading.BrokenBarrierError
    self._enter() # Block while the barrier drains.
  File "D:\buildarea\3.6.bolen-windows8\build\lib\threading.py", line 627, in _enter
    raise BrokenBarrierError
threading.BrokenBarrierError
    raise BrokenBarrierError
threading.BrokenBarrierError
ok
test_single_thread (test.test_threading.BarrierTests) ... ok

(...)

======================================================================
ERROR: test_default_timeout (test.test_threading.BarrierTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "D:\buildarea\3.6.bolen-windows8\build\lib\test\lock_tests.py", line 922, in test_default_timeout
    self.run_threads(f)
  File "D:\buildarea\3.6.bolen-windows8\build\lib\test\lock_tests.py", line 751, in run_threads
    f()
  File "D:\buildarea\3.6.bolen-windows8\build\lib\test\lock_tests.py", line 917, in f
    i = barrier.wait()
  File "D:\buildarea\3.6.bolen-windows8\build\lib\threading.py", line 612, in wait
    self._wait(timeout)
  File "D:\buildarea\3.6.bolen-windows8\build\lib\threading.py", line 650, in _wait
    raise BrokenBarrierError
threading.BrokenBarrierError