<?php
function remove_recent_comment_style() {
	global $wp_widget_factory;
	remove_action( 
            'wp_head', 
            array( $wp_widget_factory->widgets['WP_Widget_Recent_Comments'], 'recent_comments_style' ) 
        );
}
add_action( 'widgets_init', 'remove_recent_comment_style' );
?>
Remove a classe .recentcomment do head
Remove a classe .recentcomment do head
