Internal Error after install Datapusher on port 8800

Hi guys,
i have got an error in following script:

`import os
import sys
import hashlib

activate_this = os.path.join('/usr/lib/ckan/datapusher/bin/activate_this.py')
execfile(activate_this, dict(__file__=activate_this))

import ckanserviceprovider.web as web
os.environ['JOB_CONFIG'] = '/etc/ckan/datapusher_settings.py'
web.init()

import datapusher.jobs as jobs

application = web.app`
Error log writes on line 8 -- ImportError no module named contrib.fixers

Has someone an idea whats wrong with my config?

The failure is reported in the shown startup script at line 8, while importing ckanserviceprovider.web; begin by checking the environment activated through /usr/lib/ckan/datapusher/bin/activate_this.py and the referenced contrib.fixers module. Done means the Datapusher application initializes on port 8800 without the ImportError.

Written by the indexing model from the issue text.