There are not really any unittest that tests this functionality so this is not caught but the following examples have changes since 1.5.0
1.5.0

Master

1.5.0

Master

(http://matplotlib.org/devdocs/mpl_toolkits/axes_grid/examples/inset_locator_demo2.png)
1.5.0

Master

1.5.0

Master

It's likely that this is only one or two issues.