Index: wp-admin/plugins.php
===================================================================
--- wp-admin/plugins.php	(revision 15274)
+++ wp-admin/plugins.php	(working copy)
@@ -13,7 +13,7 @@
 
 	if ( empty($menu_perms['plugins']) && ! is_super_admin() )
 		wp_die( __( 'Cheatin’ uh?' ) );
-	else if ( $menu_perms['plugins'] != 1 && is_super_admin() )
+	else if ( ( empty( $menu_perms['plugins'] ) || $menu_perms['plugins'] != 1 ) && is_super_admin() )
 		add_action( 'admin_notices', '_admin_notice_multisite_activate_plugins_page' );
 }