MediaWiki 1.21/wmf7 2013-01-03, in Special:Version, do not shows the versions of Installed extensions.
This happened also for some others Mediawiki versions but not successive. Then now I report it.
This happen in www.mediawiki.org & test2.wikipedia.org but I do not seen it in some other wikis.
I seen this because as User:Rical, I follow the versionning of Scribunto in http://www.mediawiki.org/wiki/Extension:Scribunto/Deployment_priorities#Deployment_state
Version: 1.21.x
Severity: normal