I was trying to track down a ylim related freeze problem in pylab 0.81.  Not much luck so far, but I did run across another issue.  Can someone try this and see if it displays sensible results in the latest versions?
 
import pylab as p
p.cla()
p.plot([0,1.6], [10000, -0.05])
p.plot([0,2], [-.050, 10000])
p.xlim((-.1, 1.8))
p.ylim((-.1, 0.1))
p.show()
 
For me using TkAgg / python 2.3 I see a large filled triangle from the second plot command and nothing from the first.  Admittedly this is usually not a practial issue but I'm wondering if it's somehow related to the freeze I sometimes see when plotting data with a few points far outside of the present axis scale.
 
-- David