Traceback (most recent call last):
  File "/usr/lib/python2.5/site-packages/serpentine/recording.py", line 157, in __tick
    self.__prog.progress_fraction = self.__queue.progress
  File "/usr/lib/python2.5/site-packages/serpentine/operations.py", line 246, in __get_progress
    partial = self.__curr_oper.progress
  File "/usr/lib/python2.5/site-packages/serpentine/converting.py", line 304, in getProgress
    return self.__queue.progress
  File "/usr/lib/python2.5/site-packages/serpentine/operations.py", line 246, in __get_progress
    partial = self.__curr_oper.progress
  File "/usr/lib/python2.5/site-packages/serpentine/converting.py", line 51, in getProgress
    return self.__oper.progress
  File "/usr/lib/python2.5/site-packages/serpentine/audio.py", line 76, in <lambda>
    progress = property(lambda self: self._get_progress())
  File "/usr/lib/python2.5/site-packages/serpentine/audio.py", line 126, in _get_progress
    assert 0 <= self.__progress <= 1, self.__progress
AssertionError: 1.04906257112