Index: plugin-editor.php
===================================================================
--- plugin-editor.php	(revision 15819)
+++ plugin-editor.php	(working copy)
@@ -117,7 +117,7 @@
 		'<p>' . __('<a href="http://wordpress.org/support/" target="_blank">Support Forums</a>') . '</p>'
 	);
 
-	require_once('./admin-header.php');
+	require_once(ABSPATH . 'wp-admin/admin-header.php');
 
 	update_recently_edited(WP_PLUGIN_DIR . '/' . $file);
 
@@ -252,4 +252,4 @@
 <?php
 	break;
 }
-include("./admin-footer.php");
+include(ABSPATH . "wp-admin/admin-footer.php");
Index: network/plugin-editor.php
===================================================================
--- network/plugin-editor.php	(revision 0)
+++ network/plugin-editor.php	(revision 0)
@@ -0,0 +1,5 @@
+<?php
+
+require_once( './admin.php' );
+
+require( '../plugin-editor.php' );
\ No newline at end of file
Index: network/menu.php
===================================================================
--- network/menu.php	(revision 15819)
+++ network/menu.php	(working copy)
@@ -18,6 +18,9 @@
 $compat = array();
 $submenu = array();
 
+$submenu['plugins.php'][5]  = array( __('Plugins'), 'activate_plugins', 'plugins.php' );
+$submenu['plugins.php'][15] = array( _x('Editor', 'plugin editor'), 'edit_plugins', 'plugin-editor.php' );
+
 require_once(ABSPATH . 'wp-admin/includes/menu.php');
 
 ?>
\ No newline at end of file