matplotlibrc seems to be ignored from IPython notebook

I want to increase the default setting of saved matplotlib graphs, so I
created a file ~/.matplotlib/matplotlibrc containing the line

savefigdpi : 300

I then created a test notebook containing a single cell with the contents

import numpy as np
import matplotlib.pyplot as plt
x = np.array([1,2,3])
y = np.array([4,5,6])

When I run this within the notebook, the two png files are created fine,
but have different sizes. When I run the same code from the command line
(after saving the same commands to a script file, using


the two graphs have the same size, as desired. Does matplotlib ignore the
contents of ~/.matplotlib/matplotlibrc when called from an Ipython

By the way, this is using matplotlib 1.2.0 and Ipython 0.13.2, if it makes
any difference.

Thanks for any help.

Richard Stanton