Index: wp-includes/widgets.php
===================================================================
--- wp-includes/widgets.php	(revision 11157)
+++ wp-includes/widgets.php	(working copy)
@@ -73,7 +73,7 @@
 	/**
 	 * PHP4 constructor
 	 */
-	function WP_Widget( $id_base = false, $name, $widget_options = array(), $control_options = array() ) {
+	function WP_Widget( $id_base = false, $name = null, $widget_options = array(), $control_options = array() ) {
 		$this->__construct( $id_base, $name, $widget_options, $control_options );
 	}
 
@@ -86,9 +86,9 @@
 	 *	 - width
 	 *	 - height
 	 */
-	function __construct( $id_base = false, $name, $widget_options = array(), $control_options = array() ) {
+	function __construct( $id_base = false, $name = null, $widget_options = array(), $control_options = array() ) {		
 		$this->id_base = empty($id_base) ? preg_replace( '/(wp_)?widget_/', '', strtolower(get_class($this)) ) : $id_base;
-		$this->name = $name;
+		$this->name = is_null($name) ? get_class($this) : $name;
 		$this->option_name = 'widget_' . $this->id_base;
 		$this->widget_options = wp_parse_args( $widget_options, array('classname' => $this->option_name) );
 		$this->control_options = wp_parse_args( $control_options, array('id_base' => $this->id_base) );