Easy install has a very awful feature, whenever you install something as an egg it will prepend that path to your sys.path on runtime so your PYTHONPATH variable will be after all those eggs (which normally or at least for my way to work is completely fuck up).
To fix this locate the easy-install.pth file of your python installation (
$ sudo locate easy-install.pth, in my case it was /usr/local/lib/python2.7/dist-packages/easy-install.pth) and remove all lines with
import sys. And there you go, fixed.