Combining authors and wikis parameter doesn't seem to work in the Activity Stream macro

For example on xwiki.org:

• http://www.xwiki.org/xwiki/bin/view/XWiki/XWikiUserProfileSheet has the following:

  {{activity authors="${doc.fullName}" wikis="xwiki,platform,enterprise,manager,code,dev,watch,xeclipse,xoffice,contrib" /}}
  

• But if you go on a user profile you'll see it lists only activity in the main wiki. For example: http://www.xwiki.org/xwiki/bin/view/XWiki/VincentMassol