title: docker ps shows empty list
body: <p>I built a docker image from a docker file. Build said it succeeded. But when I try to show docker containers through <code>docker ps</code> (also tried <code>docker ps -a</code>), it shows an empty list. What is weird is that I'm still able to somehow push my docker image to dockerhub by calling <code>docker push "container name"</code>.</p>
  
  <p>I wonder what's going on? I'm on Windows 7, and just installed the newest version of dockertoolbox.</p>