Problems with series of plots


I'm trying to plot a series of graphs

# -*- coding: UTF-8 -*-

# Dr. Markus Faust
# markus.faust@+>>no-spam<<

from numarray import *
from matplotlib.matlab import *

x = arange(400.)*0.01+1.
y = x**2*exp(x)

for i in range(3):
    lines=semilogy(x, abs(y), 'r-')
    set(lines, 'linewidth', 2.0)
    fname = 'test' + str(i) +'.png'
    savefig(fname, dpi=250)

With matplotlib-0.61.0-numarray0.9-win32-py2.3 this works as it should.
One plot windows occurs, I click it away and the next occurs.

But with matplotlib-0.62.4.win32-py2.3.exe the program behaves strange.
The first windows occurs and I can click it away but the next windows
can not be controlled anymore. Is that anticipated?

I'm working on a Windows XP Prof. PC with Python 2.3.4 and numarray 0.9.