title: Exception raised when running ipython notebook
body: <p>I used to have ipython notebook working correctly in fedora, but then tried to get ipython notebook for julia with Pkg.build("IJulia") and Pkg.add("IJulia").
  After doing this and updating my ipython version with pip I could not run ipython notebook anymore, the next exception was raised over and over again:</p>
  
  <pre><code>ERROR:root:Exception in I/O handler for fd 6
  Traceback (most recent call last):
    File "/usr/lib64/python2.7/site-packages/zmq/eventloop/ioloop.py", line 346, in start
      self._handlers[fd](fd, events)
  KeyError: 6
  ^C2014-08-12 22:51:35.024 [NotebookApp] CRITICAL | received signal 2, stopping
  </code></pre>
  
  <p>Any help would be very much appreciated.
  Thanks in advance :)</p>