Error in Boxplot

Dear List,

boxplots are not plotted correctly in case the 'x' argument has an even
number of elements. So when I do:

import matplotlib.pyplot as plt
import numpy as np

r_odd = np.array([1,2,3,4,5])

I get the correct boxplot but when I do:

r_even = np.array([1,2,3,4,5,6])

I get a median at 4 which is incorrect. This is also easily compared
with the matlab boxplot function. Do I maybe miss anything here? I use
the most recent svn checkout (v0.98.6svn).