[Plugin: Flash Feed Scroll Reader] call_user_func_array Error

Any idea’s?

Warning: call_user_func_array() [function.call-user-func-array]: First argument is expected to be a valid callback, ‘ffsr_wp_header’ was given in /usr/www/users/******/wp-includes/plugin.php on line 339

http://wordpress.org/extend/plugins/flash-feed-scroll-reader/