This plugin hasn't been updated in over 2 years. It may no longer be maintained or supported and may have compatibility issues when used with more recent versions of WordPress.
For the reasons cited above, this plugin is not publicly listed in the repository.
Many of these plugins I use every day, and they continue to work fine on 3.4.2. They have no need of an update, and are still valid for listing in the public directory. I've tried committing trivial changes to the code and the readme, but neither has removed the message. According to the faq:
Last updated time
Time of last check in to the appropriate directory (trunk/ or the stable tag directory) after a version number change.
Do I really need to push a new version number, with no change to the plugin, in order to get the plugins re-listed? Is that not completely ridiculous? I realise this is an edge case, but surely if a plugin author has gone to the effort of updating the "tested up to" field in their readme.txt, that's a signal that the plugin is still "actively maintained" and so fit for inclusion in the directory?