In my quest to vanquish all doc buildtime warnings, I came across this problem in the geo_demo.examples/pylab_examples/geo_demo.py issues the following RuntimeWarnings. Can the code or example be re-worked to not issue warnings? I'm running stock python2.7 on ubuntu 11.04, 64bit.

msierig@pinchiepie:pylab_examples> python geo_demo.py
/home/msierig/dev/lib/python2.7/site-packages/matplotlib/projections/geo.py:438: RuntimeWarning: invalid value encountered in divide
delta = -(theta + np.sin(theta) - pi_sin_l) / (1 + np.cos(theta))
/home/msierig/dev/lib/python2.7/site-packages/matplotlib/projections/geo.py:279: RuntimeWarning: invalid value encountered in divide
x = (cos_latitude * np.sin(half_long)) / sinc_alpha
/home/msierig/dev/lib/python2.7/site-packages/matplotlib/projections/geo.py:280: RuntimeWarning: invalid value encountered in divide
y = (np.sin(latitude) / sinc_alpha)