The plugin generated 264 characters of unexpected output during activation. If you notice “headers already sent” messages, problems with syndication feeds or other issues, try deactivating or removing this plugin. Using version 1.7.1. If I use 1.7 I receive the same error message.
If I use version 1.6.2 with WP 3.5.1 I do not receive the warning message and the plugin seems to work.