Index: wp-includes/post-template.php
===================================================================
--- wp-includes/post-template.php	(revision 21039)
+++ wp-includes/post-template.php	(working copy)
@@ -498,9 +498,11 @@
 	if ( is_user_logged_in() )
 		$classes[] = 'logged-in';
 
-	if ( is_admin_bar_showing() )
+	if ( is_admin_bar_showing() ) {
 		$classes[] = 'admin-bar';
-
+		$classes[] = 'no-customize-support';
+	}
+	
 	if ( get_background_color() || get_theme_mod( 'background_image' ) || get_theme_support( 'custom-background', 'default-image' ) )
 		$classes[] = 'custom-background';