Getting resize_event to work

Trying to get resize event to work, but either I don't understand the definition of when resize_event should work, or it's broken.

for example

···

=======================
from matplotlib import pylab , numerix

def GotResizeEvent( event ):
    print 'Resize event detected'

def GotDrawEvent( event ):
    print 'Draw event detected'

X = range(0, 200)
Y = pylab.sin(X)

r = pylab.plot(X,Y)
pylab.connect( 'resize_event', GotResizeEvent)
pylab.connect( 'draw_event', GotDrawEvent)
pylab.show()

Will only get draw_events as I zoom in on the data, never a resize event?
I also get draw_events as I resize the window itself, but never a resize_event.

So my question, .. what user activity triggers a resize event?

Numerix Version: numpy 1.0
MatPlotLib Version: 0.87.7

Steve