Matplotlib legend location

# -*- coding: utf-8 -*-
"""
Created on Thu Apr 12 11:16:03 2012

Using the current stable version of pythonxy on Windows 7 32bit
Author: Jonathan


Notice how the figure box is not placed correctly, effectively missing the
legend entirely
"""

import matplotlib.pyplot as plt
import numpy as np

x = np.arange(-2*np.pi, 2*np.pi, 0.1)
fig = plt.figure(1)
ax = fig.add_subplot(111)
ax.plot(x, np.sin(x), label='Sine')
ax.plot(x, np.cos(x), label='Cosine')
ax.plot(x, np.arctan(x), label='Inverse tan')
handles, labels = ax.get_legend_handles_labels()
lgd = ax.legend(handles, labels, loc='upper center', bbox_to_anchor=(0.5,-0.1))
ax.grid('on')
fig.savefig('samplefigure', bbox_extra_artists=(lgd,), bbox_inches='tight')