Took from MPOS Quick Install.. The best way to make sure Python Stratum will work is to do;
sudo apt-get install python-twisted python-mysqldb python-dev python-setuptools python-memcache python-simplejson python-pylibmc
sudo easy_install -U distribute
Then execute;
cd ~
cp stratum-mining/conf/config_sample.py stratum-mining/conf/config.py
nano stratum-mining/conf/config.py
This will backup the config and then put you in an editor so you can edit your config (if you haven't already done so).
Make sure you run those commands, then run the stratum server. It _should_ work. If not, then double check everything.