Segmentation fault with statsmodels
I am getting an intermittent fault when creating a series of plots - but I am not sure this is sufficient information to determine the cause.

```
/usr/local/lib/python2.7/dist-packages/numpy/core/scalarmath.so
/usr/local/lib/python2.7/dist-packages/numpy/linalg/lapack_lite.so
/usr/local/lib/python2.7/dist-packages/pandas-0.11.0-py2.7-linux-x86_64.egg/pandas/lib.so
/usr/local/lib/python2.7/dist-packages/pandas-0.11.0-py2.7-linux-x86_64.egg/pandas/algos.so
/usr/local/lib/python2.7/dist-packages/pandas-0.11.0-py2.7-linux-x86_64.egg/pandas/index.so
/usr/local/lib/python2.7/dist-packages/numpy/core/multiarray.so
/usr/local/lib/python2.7/dist-packages/statsmodels-0.5.0-py2.7-linux-x86_64.egg/statsmodels/nonparametric/_smoothers_lowess.so
/usr/local/lib/python2.7/dist-packages/numpy/fft/fftpack_lite.so
/usr/local/lib/python2.7/dist-packages/pandas-0.11.0-py2.7-linux-x86_64.egg/pandas/hashtable.so
/usr/local/lib/python2.7/dist-packages/numpy/core/umath.so
/usr/local/lib/python2.7/dist-packages/numpy/lib/_compiled_base.so
/usr/local/lib/python2.7/dist-packages/numpy/random/mtrand.so
/usr/local/lib/python2.7/dist-packages/statsmodels-0.5.0-py2.7-linux-x86_64.egg/statsmodels/tsa/kalmanf/kalman_loglike.so
/usr/local/lib/python2.7/dist-packages/pandas-0.11.0-py2.7-linux-x86_64.egg/pandas/tslib.so
/usr/local/lib/python2.7/dist-packages/pandas-0.11.0-py2.7-linux-x86_64.egg/pandas/_sparse.so
/usr/local/lib/python2.7/dist-packages/pandas-0.11.0-py2.7-linux-x86_64.egg/pandas/_parser.so
/usr/local/lib/python2.7/dist-packages/statsmodels-0.5.0-py2.7-linux-x86_64.egg/statsmodels/nonparametric/linbin.so
```
