[Plugin: phpbb_recent_topics] Fatal error: Call to undefined method

phpBB Recent Topics News
Fatal error: Call to undefined method WP_Error::get_items() in …/wp-content/plugins/phpbb-recent-topics/display/admin-options.php on line 239

The fatal error screws up the display of the admin section.

http://wordpress.org/extend/plugins/phpbb-recent-topics/