I just tried and the plugin seems to install ok for me.
> The list of available plugins is very short, and a refresh does not make any difference.
I have experienced this kind of thing in the past. Usually it means there are intermittent problems with the plugin list file(s) on grails.org (sometimes they get corrupted when someone uploads a new plugin version). It could be the problem is already fixed. Could you please try refreshing the list again and try again to install your plugin.
If it still not working, let me know and we will dig a little deeper.
Kris De Volder -- SpringSource