mpl 2.0b4

axes([.9, .9, -.8, -.8]); plot([1, 2])

Interative zooming seems to work but fails to draw the rubber-band; I suspect it is because the implementation of drag_zoom assumes that the axes' bbox extents are in the "standard" order:

            x1, y1, x2, y2 = a.bbox.extents
            x, lastx = max(min(x, lastx), x1), min(max(x, lastx), x2) # probably happens here
            y, lasty = max(min(y, lasty), y1), min(max(y, lasty), y2)

(and I'd guess there may be other issues elsewhere).

Not sure whether we want to do something about it (which may be as simple as reordering the bbox extents in the Axes constructor, or raising an exception if the width or height are negative), or just document that this is not supported and live with it.