Version:            (using KDE Devel)
Installed from:    Compiled sources
Compiler:          gcc version 3.2.3 20030422 (Gentoo Linux 1.4 3.2.3-r1, propolice) 
OS:          Linux

I try to do script in PHP, that will read some file, send it to the browser and delete it afterwards. It looks like this:

if (file_exists('file')) {
   header("Content-type: octet/stream");
   header("Content-Disposition: attachment; filename=".$file['name']);
   readfile('file');
   unlink('file');
} else {
   // redirect to "page X"
}

...when I try it in Konqueror, it shows the "Save As" dialog and then it saves content of "page X" to the file. I looked into the logs and it seems like two requests were sent and content of the file was html of the page, it redirects to when no file is found (original file was deleted after the first request).

Logs from apache:
127.0.0.1 - - [05/Aug/2003:19:12:39 +0200] "GET /path/to/index.php?l=args HTTP/1.1" 200 207708 "-" "Mozilla/5.0 (compatible; Konqueror/3.1; Linux)"
127.0.0.1 - - [05/Aug/2003:19:12:40 +0200] "GET /path/to/index.php?l=args HTTP/1.1" 302 5 "-" "Mozilla/5.0 (compatible; Konqueror/3.1; Linux)"

I use recent -cvs version of kdelibs/kdebase and haven't tested it in any other version of Konq. In Mozilla, IE and Links2 it works as expected.