When trying to save a figure in matplotlib 1.5.0 with backend:Qt4Agg and backend.qt4:PySide the save button is not functional. The save dialog opens and then immediately closes.

# Use %matplotlib to prevent segfault reported in issue #5687
%matplotlib 
import matplotlib.pyplot as plt
plt.plot(range(10))

Click the save button.
plt.savefig() still works.
I have been able to reproduce this behavior on Mac (OSX 10.11) in both Enthought and Anaconda's matplotlib 1.5.0.