When I installed the Adafruit_Python_BluefruitLE outside of my virtualenv, the example program could not find it. Running `pip install git+git://github.com/playi/Adafruit_Python_BluefruitLE@928669a#egg=Adafruit_BluefruitLE` after `virtualenv --python=/usr/bin/python2.7 --no-site-packages venv` worked better for me.