Readfile() Download Issues

Hi, I'm having trouble supporting Internet Explorer 5.5 and earlier versions in a PHP download script. People are reporting that the file comes out as 'download.htm'. Here is the code in my download.php: $len = filesize($file); header("Content-type: application/zip"); header("Content-Length: $len"); header("Content-Disposition: attachment; filename=$filename"); readfile($file); Other browsers appear to work fine. An thoughts? Thanks, Steven J. Walker Walker Effects www.walkereffects.com steve@walkereffects.com