title: Can't see matplotlib plots in iPython notebook
body: <p>I'm trying to show pandas-generated plots in iPython notebooks (running with <code>pylab=inline</code>), but these have mysteriously stopped working—I'll do something like:</p>
  
  <pre><code>In [6]: pd.Series([0,2,4,3,8]).plot()
  Out[6]: &lt;matplotlib.axes.AxesSubplot at 0x10e69e110&gt;
          &lt;matplotlib.figure.Figure at 0x10eb40d90&gt;
  </code></pre>
  
  <p>Note: there's no plots here, just the text.</p>
  
  <p>I do, however, get these errors in the console where I'm running iPython:</p>
  
  <pre><code>libpng warning: Application built with libpng-1.5.18 but running with 1.6.10
  </code></pre>
  
  <p>How do I sort this out and get plots working again?</p>
  
  <p>(I have libpng installed through homebrew, iPython v.1.1.0, matplotlib v.1.3.1)</p>
  
  <hr>
  
  <p>UPDATE: Now I'm using iPython v.2.1.0.</p>
  
  <p>I still get the libpng error, but in the notebook I now get</p>
  
  <pre><code>In [2]: pd.Series([0,2,4,3,8]).plot()
  Out[2]: &lt;matplotlib.axes.AxesSubplot at 0x112821110&gt;
          /Library/Python/2.7/site-packages/IPython/core/formatters.py:239: FormatterWarning: Exception in image/png formatter: Could not create write struct
            FormatterWarning,
          &lt;matplotlib.figure.Figure at 0x112788a50&gt;
  </code></pre>
  
  <p>So... progress?</p>
  
  <p>(I am also now using <code>%pylab inline</code> in the document, instead of using it as a command-line flag.)</p>