plotting without ticks -- bug?

Hi all, I'm trying to get some figures ready, but I've

    > encountered what may be a bug demonstrated by a trivial
    > program:

Yeah, it's a bug. Replace the autoscale function in the Locator base
class, which currently raises the NotImplementedError, with

    def autoscale(self):
        'autoscale the view limits'
        return self.dataInterval.get_bounds()

Should cure what ails you.