odd placement of zero

When I run this script from scipy import * from

    > matplotlib.matlab import * def f(x): return 2*x**3-5*x
    > x=(arange(2001)-1000)/100.0 plot(x,f(x))
    > axis([-10,10,-20,20]) show() plot(x,f(x)) axis([-2,2,-5,5])
    > show()

    > I get an odd placement of the zero on the x axis in the
    > second plot. If I cut out the first plot, this does not
    > happen. How am I causing this?

    > Thank you, Alan Isaac

Calling show multiple times in one script is backend dependent and not
supported. See http://matplotlib.sf.net/faq.html#SHOW. I haven't
been able to replicate your bug - what version of matplotlib are you
using and what backend? Can you write an example w/o multiple show
calls that produces it?

What do you mean that the zero on the x axis has an odd placement?
Can you save a PNG and send it to me off list?