Index: wp-includes/js/media-views.js
===================================================================
--- wp-includes/js/media-views.js	(revision 23924)
+++ wp-includes/js/media-views.js	(working copy)
@@ -3934,7 +3934,7 @@
 
 			// Handle checkboxes.
 			} else if ( $setting.is('input[type="checkbox"]') ) {
-				$setting.attr( 'checked', !! value );
+				$setting.attr( 'checked', !! value && value !== 'false' ); //check for false or string 'false'
 			}
 		},