[gtkextra] artifacts on zooming

[bhendrick <bhe...@kn...>]

I have a plot that contains a large number of dataset > 1700
The plot is a network message plot with time along the bottom
and one dataset per message flowing between one y value and
another. I allow users to zoom in on the plot because some
messages occur very close in time and you have to to resolve
the messages. What happens is when you zoom in very close
you start seeing extra lines on the screen that don't
represent the real data. Zoom out a little and they go away
zoom back in and they reappear. This is not a problem of
new messages being resolved. All my messages have labels on them
these "artifacts" do not. Anybody got any ideas?
I am using .16 release