Index: wp-includes/widgets.php
===================================================================
--- wp-includes/widgets.php	(revision 7152)
+++ wp-includes/widgets.php	(working copy)
@@ -877,7 +877,7 @@
 			<?php echo $before_title . $title . $after_title; ?>
 			<ul>
 			<?php  while ($r->have_posts()) : $r->the_post(); ?>
-			<li><a href="<?php the_permalink() ?>"><?php if ( get_the_title() ) the_title(); else the_ID(); ?> </a></li>
+			<li><a href="<?php the_permalink() ?>" title="<?php if ( get_the_title() ) the_title(); else the_ID(); ?>"><?php if ( get_the_title() ) the_title(); else the_ID(); ?> </a></li>
 			<?php endwhile; ?>
 			</ul>
 		<?php echo $after_widget; ?>