Unknown Path Error

I have the same problem as Andrew Kelly

I did the example code below (from coords_demo.py) to reproduce the bug :

#!/usr/bin/env python
An example of how to interact with the plotting canvas by connecting
to move and click events
import sys
from pylab import *

t = arange(0.0, 1.0, 0.01)
s = sin(2*pi*t)
ax = subplot(111)
ax.axhline(0.5, 0, 1)

def on_move(event):
    # get the x and y pixel coords
    x, y = event.x, event.y
       if event.inaxes:
        ax = event.inaxes # the axes instance
        print 'data coords', event.xdata, event.ydata
        lst = ax.hitlist(event)
def on_click(event):
    # get the x and y coords, flip y from top to bottom
    x, y = event.x, event.y
    if event.button==1:
        if event.inaxes is not None:
            print 'data coords', event.xdata, event.ydata

binding_id = connect('motion_notify_event', on_move)
connect('button_press_event', on_click)

if "test_disconnect" in sys.argv:
    print "disconnecting console coordinate printout..."