Forcing the browser to download a file - this may help

I had a folder outside public_html which contained files that needed to be available for download to certain users.

The problem was that the files where not downloading correctly in various browsers - eg a pdf file would download correctly in firefox but ie would display this message:

"internet explorer cannot download

internet explorer was not able to open this Internet site. The requested site is either unavailable or cannot be found. Please try again later.

The problem was with the headers. The following headers work with IE6, Firefox and IE7. "

<?php
  $header[] = "Pragma: public";
  $header[] = "Expires: 0";
  $header[] = "Cache-Control: must-revalidate, post-check=0, pre-check=0";
  $header[] = "Cache-Control: public";
  $header[] = "Content-Description: File Transfer";
  $header[] = "Content-type: application/octet-stream";
  $header[] = "Content-Disposition: attachment; filename=\"$filename\"";
  $header[] = "Content-Transfer-Encoding: binary";
  $header[] = "Content-Length: " .filesize($file);
?>

code a combination from quickfile module, http://richardlynch.blogspot.com/2006_06_01_archive.html, and http://www.zubrag.com/scripts/download.php .

Please post headers here that you know that works with a wide variety of browsers!