Index: wp-admin/js/widgets.dev.js
===================================================================
--- wp-admin/js/widgets.dev.js	(revision 19788)
+++ wp-admin/js/widgets.dev.js	(working copy)
@@ -253,6 +253,9 @@
 			title = title.replace(/<[^<>]+>/g, '').replace(/</g, '&lt;').replace(/>/g, '&gt;');
 			$(widget).children('.widget-top').children('.widget-title').children()
 				.children('.in-widget-title').html(': ' + title);
+		} else if ( typeof title != "undefined" ) { // empty string
+			$(widget).children('.widget-top').children('.widget-title').children()
+				.children('.in-widget-title').empty();
 		}
 	},