After further analysis and downgrading python2.7 this issue is not reproducible with python2.7 2.7.3-14ubuntu1 (it started with python2.7 2.7.3-15ubuntu1) , so it's potentially a regression introduced in python2.7 2.7.3-15ubuntu1
After further analysis and downgrading python2.7 this issue is not reproducible with python2.7 2.7.3-14ubuntu1 (it started with python2.7 2.7.3-15ubuntu1) , so it's potentially a regression introduced in python2.7 2.7.3-15ubuntu1