Sikuli X: on exit you get a sys.exit exception

alwas got exception when test is done, even if the test is empty

empty testsuite:
class TestDemo(unittest.TestCase):
    def setUp(self):
        setThrowException(False)

    def tearDown(self):
        setThrowException(True)

    def test_empty(self):
        self.failUnless(True)

result:
test_empty (__main__.TestDemo) ...
DELTA_TIME: 0:00:01
TIME: 2011-01-17 16:46:32ok

----------------------------------------------------------------------
Ran 1 test in 0.000s

OK
Exception in thread "main" Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "Lib\sikuli\Sikuli.py", line 153, in exit
    sys.exit(code)
SystemExit: 0