Index: wp-includes/functions.php
===================================================================
--- wp-includes/functions.php	(revision 12131)
+++ wp-includes/functions.php	(working copy)
@@ -2265,6 +2265,7 @@
 		'asf|asx|wax|wmv|wmx' => 'video/asf',
 		'avi' => 'video/avi',
 		'divx' => 'video/divx',
+		'flv' => 'video/x-flv',
 		'mov|qt' => 'video/quicktime',
 		'mpeg|mpg|mpe' => 'video/mpeg',
 		'txt|c|cc|h' => 'text/plain',