Exporting to HTML or viewing in NBViewer does not show contents of TOC.

[matthew-egbert]

When trying to export a notebook with a table of contents the floating window appears, but with no content.

As an example of this, see this nbviewer page that demonstrates this extension.

http://nbviewer.ipython.org/github/dpsanders/IPython-notebooks/blob/master/IPython/nbtoc%20extension%20for%20IPython%20.ipynb