Hi pyx,
I have made two changes to my copy of pyx.
(1) I've made the number of significant figures on the tick labels the same
by padding with zeros.
So on my figure the tick labels on the vertical axis were:
0.8 1.2 1.6 2  2.4 2.8 3.2
With the change the 2 now reads 2.0. Similarly on the horizontal axis.

(2) With a log plot, if the size of the error bar is greater than the size of the
data point then the function  axis.convert returns nan's which go into the
array sharedata.vrange. This causes the error bar not to be displayed,
which looks a bit funny. So I've changed it in this case to display the error bar to the bottom of the vertical axis. This produces figures similar to gnuplot. I find it easier on the eye to have the  rubbish data with huge error bars.

If you want these changes your welcome to then.
Otherwise thank you for pyx.