Sphinx 'only' block strange behavior

.. Quest for Sphinx Behavior documentation master file, created by
   sphinx-quickstart on Thu Feb 21 02:23:30 2013.
   You can adapt this file completely to your liking, but it should at least
   contain the root `toctree` directive.

Welcome to Quest for Sphinx Behavior's documentation!
=====================================================

Contents:

.. 	toctree::
   	:maxdepth: 2

.. 	only:: platform

	This gets displayed

	A title at another level
	------------------------

	This also gets displayed

	Similar title to headings in the rest of the document
	=====================================================

	This does not get displayed. If you use any level of heading which is used
	anywhere else in the same document, outside of the 'only' block, that title
	and anything after it within the only block will not be displayed.

	Another title at a different level
	----------------------------------

	This also does not get displayed