Here is a .rst that reproduces the problem fixed by this changes:
"description-paragraph" is extracted as translation message by
"sphinx-build -b gettext" but "term-word" isn't.
It's because nodes.term node doesn't have source information.
Source information should be added by Docutils instead of Sphinx.
A patch that fix this problem in Doctuils had been submitted:
This changes are workarond to work with docutils-0.9.1 or earlier.