Index: wp-admin/upgrade-functions.php
===================================================================
--- wp-admin/upgrade-functions.php	(revision 5342)
+++ wp-admin/upgrade-functions.php	(working copy)
@@ -188,6 +188,8 @@
 	if ( $wp_current_db_version < 5200 ) {
 		upgrade_230();
 	}
+	
+	maybe_disable_automattic_widgets();
 
 	$wp_rewrite->flush_rules();
 
@@ -1111,4 +1113,13 @@
 		die(sprintf(__('<strong>ERROR</strong>: WordPress %s requires MySQL 4.0.0 or higher'), $wp_version));
 }
 
-?>
+function maybe_disable_automattic_widgets() {
+	$plugins = __get_option( 'active_plugins' );
+	
+	if ( in_array( 'widgets/widgets.php', $plugins ) ) {
+		array_splice( $plugins, array_search( 'widgets/widgets.php', $plugins ), 1 );
+		update_option( 'active_plugins', $plugins );
+	}
+}
+
+?>
\ No newline at end of file