Error when running acceptance tests

gistfile1.txt

$ rake test:acceptance:lms["lms/djangoapps/courseware/features/video.feature"]

...

<Step: "And I see duration "1:00"">
Traceback (most recent call last):
  File "/edx/app/edxapp/venvs/edxapp/src/lettuce/lettuce/core.py", line 144, in __call__
    ret = self.function(self.step, *args, **kw)
  File "/edx/app/edxapp/edx-platform/lms/djangoapps/courseware/features/video.py", line 531, in i_see_duration
    assert duration() == parse_time_str(position)
AssertionError
<Step: "Then I see video slider at "11" seconds">
Traceback (most recent call last):
  File "/edx/app/edxapp/venvs/edxapp/src/lettuce/lettuce/core.py", line 144, in __call__
    ret = self.function(self.step, *args, **kw)
  File "/edx/app/edxapp/edx-platform/lms/djangoapps/courseware/features/video.py", line 521, in start_playing_video_from_n_seconds
    assert_equal(actual_position, int(position), "Current position is {}, but should be {}".format(actual_position, position))
  File "/usr/lib/python2.7/unittest/case.py", line 511, in assertEqual
    assertion_func(first, second, msg=msg)
  File "/usr/lib/python2.7/unittest/case.py", line 504, in _baseAssertEqual
    raise self.failureException(msg)
AssertionError: Current position is 10, but should be 11

1 feature (0 passed)
30 scenarios (28 passed)
209 steps (2 failed, 207 passed)