Yep, definitely only works on WordPress 2.5. The new version of WordPress features a totally new admin panel, so if you try to activate with that I’m not sure what will happen – possible nothing, possibly you will get a big mess, I’m not sure. At any rate, I know it will not work for sure.
I originally hacked up the admin interface for my own purposes, but I never turned it into a plugin. So when I realised my old hacked up files wouldn’t work anymore I decided to turn it into a plugin. My old route was pretty dodgy as it was as I rarely upgraded my WordPress installs as I was always concerned my hack might break each time. The new plugin route is unlikely to ever break on upgrading unless there is a major change to WordPress. And with a bunch of other people using it I have far more motivation to keep it updated ” title=”Smiley” />