When saving changes on the Widgets page, my browser was being redirected to http:///wp-admin/ instead of http://blogname.com/wp-admin/.
To fix this, I applied this patch.
--- widgets.php.orig 2008-07-04 18:17:19.000000000 -0700
+++ widgets.php 2008-07-04 18:16:08.000000000 -0700
@@ -228,7 +228,7 @@
<div class="wrap">
- <form id="widgets-filter" action="" method="get">
+ <form id="widgets-filter" action="<?php echo clean_url( remove_query_arg( $query_args ) ); ?>" method="get">
<h2><?php _e( 'Widgets' ); ?></h2>
<p id="widget-search">
@@ -283,7 +283,7 @@
</div>
</div>
- <form id="widget-controls" action="" method="post">
+ <form id="widget-controls" action="<?php echo clean_url( remove_query_arg( $query_args ) ); ?>" method="post">
<div id="current-widgets-head" class="widget-liquid-right">