My use case is that I create a series of histograms, with "orientation=horizontal", and "normed=True" in matplotlib 1.1.1. I space them out in a single axes, using the "bottom" argument to set where along the x axis they should appear. This works great for 1.1.1, but is broken in 1.2.
Do you need code, or is the problem obvious enough? Exact same code running with different matplotlib versions installed:

Matplotlib 1.1.1

Matplotlib 1.2.0