Traceback (most recent call last):
  File "/usr/bin/unattended-upgrade", line 374, in <module>
    main()
  File "/usr/bin/unattended-upgrade", line 177, in main
    cache = MyCache()
  File "/usr/bin/unattended-upgrade", line 31, in __init__
    apt.Cache.__init__(self)
  File "/usr/lib/python2.6/dist-packages/apt/cache.py", line 62, in __init__
    self.open(progress)
  File "/usr/lib/python2.6/dist-packages/apt/cache.py", line 75, in open
    self._cache = apt_pkg.GetCache(progress)
SystemError: E:read, still have 9412541 to read but none left, E:The package lists or status file could not be parsed or opened.