title: Unable to plot graphs in iPython notebook, OSX 10.6
body: <p>i am trying to get inline graphs working in iPython notebook.. i begin by starting ipython with the command ipython notebook --pylab inline.</p>
  
  <p>when i try to use the plot() function i get the following error</p>
  
  <p><img src="https://i.stack.imgur.com/dKCBv.png" alt="enter image description here"></p>
  
  <p>im running on OSX 10.6.8 and running ipython out of a virtualenv i have matplotlib and libpng installed</p>
  
  <p>i also get this warning in the terminal</p>
  
  <p>libpng warning: Application built with libpng-1.2.41 but running with 1.5.13</p>
  
  <p>and plot() works normally when i use ipython in the terminal only when i use ipython notebook i get this error.. can someone help me with this..?</p>