Index: wp-includes/default-filters.php
===================================================================
--- wp-includes/default-filters.php	(revision 23294)
+++ wp-includes/default-filters.php	(working copy)
@@ -192,6 +192,7 @@
 add_filter( 'editable_slug',            'urldecode'                           );
 add_filter( 'editable_slug',            'esc_textarea'                        );
 add_filter( 'nav_menu_meta_box_object', '_wp_nav_menu_meta_box_object'        );
+add_filter( 'sanitize_file_name',       'remove_accents'                      );
 
 // Actions
 add_action( 'wp_head',             'wp_enqueue_scripts',              1     );