Also reproduced on Ubuntu Lucid/Core 2 Duo with a very low switch
interval and -j4. It takes more repetitions than on the i7:

$ ./python -m test -uall -F -j4  test_importlib 
[...]
[224] test_importlib
[225] test_importlib
[226/1] test_importlib
test test_importlib failed -- Traceback (most recent call last):
  File "/home/stefan/pydev/cpython/Lib/test/test_importlib/test_locks.py", line 80, in test_deadlock
    self.assertEqual(results.count((True, False)), 1)
AssertionError: 2 != 1