Index: wp-admin/admin-ajax.php
===================================================================
--- wp-admin/admin-ajax.php	(revision 18589)
+++ wp-admin/admin-ajax.php	(working copy)
@@ -1151,8 +1151,7 @@
 	if ( $order )
 		update_user_option($user->ID, "meta-box-order_$page", $order, true);
 
-	if ( $page_columns )
-		update_user_option($user->ID, "screen_layout_$page", $page_columns, true);
+	update_user_option($user->ID, "screen_layout_$page", $page_columns, true);
 
 	die('1');
 	break;