Index: wp-admin/menu-header.php
===================================================================
--- wp-admin/menu-header.php	(revision 11580)
+++ wp-admin/menu-header.php	(working copy)
@@ -115,7 +115,7 @@
 
 				$menu_hook = get_plugin_page_hook($sub_item[2], $item[2]);
 
-				if ( ( ('index.php' != $sub_item[2]) && file_exists(WP_PLUGIN_DIR . "/{$sub_item[2]}") ) || ! empty($menu_hook) ) {
+				if ( ( ('index.php' != $sub_item[2]) && @file_exists(WP_PLUGIN_DIR . "/{$sub_item[2]}") ) || ! empty($menu_hook) ) {
 					// If admin.php is the current page or if the parent exists as a file in the plugins or admin dir
 					$parent_exists = (!$admin_is_parent && file_exists(WP_PLUGIN_DIR . "/{$item[2]}") && !is_dir(WP_PLUGIN_DIR . "/{$item[2]}") ) || file_exists($item[2]);
 					if ( $parent_exists )