lines go "zig-zag'

Hi,

I have plotted my data (x,y) to line plot without axis
adjustments right. But if I scale y axis (with 'axis')
and cut some maximal values of y data out, it seems
that y is drawn within new margins of y axis, but just
translated some way. (small graphs PNG attached). PNG
made with savefig has different "zig-zags". My graphs
SHOULD NOT have any data line x(0-3.4). It makes no
problem if I scale x axis. My script:

import pylab as P
    
P.plot(x, y, 'k-', label='Total', linewidth='2')
P.axis([0.0,15,-0.4,0.5])
P.xlabel('Distance, A')
P.ylabel('Energy')
P.grid(True)
P.savefig('scatter_demo',dpi=150)
P.show()

Arturas
P.S. MS XP / python 2.4 / matplotlib-0.87.7

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