I'm also attempting to set up simple captcha on a joyent accelarator, and am running on the same problem. By clicking on the link gogonova.com, it seems like you guys have fixed the problem. Was the problem with rmagick/imagemagick? Does the version of the plugin that doesn't use them solve the issue? It seems like rmagick has been added back in to the newest version. Any help/insight at all would be appreciated.