Traceback (most recent call last):
  File "/usr/share/software-center/softwarecenter/backend/reviews.py", line 600, in _on_review_stats_data
    s.rating_spread = simplejson.loads(getattr(r, "histogram", 0))
  File "/usr/lib/python2.7/dist-packages/simplejson/__init__.py", line 385, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python2.7/dist-packages/simplejson/decoder.py", line 402, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
TypeError: expected string or buffer