вот примерный файл для 404
[CODE]
include_once($_SERVER['DOCUMENT_ROOT'].'/bitrix/modules/main/include/urlrewrite.php');
$sapi_type = php_sapi_name();
if ($sapi_type=="cgi")
header("Status: 404");
else
header("HTTP/1.1 404 Not Found");
@define("ERROR_404","Y");
require($_SERVER["DOCUMENT_ROOT"]."/bitrix/header.php");
$APPLICATION->SetTitle("404 - HTTP not found");
$APPLICATION->IncludeComponent("bitrix:main.map", ".default", Array(
"LEVEL" => "3",
"COL_NUM" => "2",
"SHOW_DESCRIPTION" => "Y",
"SET_TITLE" => "Y",
"CACHE_TIME" => "3600"
)
);
require($_SERVER["DOCUMENT_ROOT"]."/bitrix/footer.php");?>
[/CODE]
Т.е. обязательно должно быть header("HTTP/1.1 404 Not Found");