I am currently using version 1.0.2 and initially, the plugin did not work after installing, activating and configuring it.
I add my taxonomies in the 'init' event, as prescribed (http://codex.wordpress.org/Function_Reference/register_taxonomy#Usage). Your plugin also hooks into the 'init' event to get the taxonomy but somehow this happens before my taxonomies are registered.
I've fixed it as follows
in the constructor of the WordPress_Radio_Taxonomy class, I've set the priority of the get_taxonomy hook to 11 in stead of 10 (default) by changing line #16 from
add_action( 'init', array(&$this, 'get_taxonomy'));
add_action( 'init', array(&$this, 'get_taxonomy'), 11);
Hope you can update the plugin so I won't have to work with a modified version.