Matplotlib bug on OS X
The latest matplotlib (v1.3.x) code has a bug that causes it to fail on text containing non-ascii characters. As a result, STAMP crashes. This problem has been reported on other platforms, and a workaround is posted at https://github.com/matplotlib/matplotlib/pull/2307. Pulling the latest version of matplotlib should resolve this problem.
Thanks goes to Peter Sterk for bringing this to my attention