Last modified: 2013-11-07 10:58:53 UTC
Noticed on mediawiki.org, in the VisualEditor toolbar, Menu icon, last item: <visualeditor-mweditmodesource-title>. Special:Version says mw.o is currently running 1.23wmf2 (88c7b3f).
Sounds like a caching issue with ResourceLoader.
On further inspection looks like a deployment / server-side caching issue. Definitely nothing wrong with the code though.
Working now.