Page cache makes browser cache pages for 2 weeks

I had the following caching problem on a client's site running Drupal 5. I'm pretty sure this issue still exists in Drupal 6 too but haven't tested it yet.

Pages were "cached for two weeks" (because of the mod_rewrite in .htaccess) on client side.

The client runs Apache 1.3.

I found a solution in my case via http://drupal.org/node/213078 but since this was in a deprecated forum, and never got into core, I tought it was good to mention this in the issue queue.

PROBLEM

With Drupal's default .htaccess file:

<IfModule mod_expires.c>
  # Enable expirations.
  ExpiresActive On
  # Cache all files for 2 weeks after access (A).
  ExpiresDefault A1209600
  # Do not cache dynamically generated pages.
  ExpiresByType text/html A1
</IfModule>

I get the following headers:

HTTP/1.x 200 OK
Date: Thu, 09 Oct 2008 22:18:08 GMT
Server: Apache/1.3.33 (Debian GNU/Linux) FrontPage/5.0.2.2635 mod_ssl/2.8.22 OpenSSL/0.9.7e
Cache-Control: no-cache, must-revalidate, max-age=1209600
Expires: Mon, 26 Jul 1997 05:00:00 GMT, Thu, 23 Oct 2008 22:18:08 GMT
X-Powered-By: PHP/5.2.5-0.dotdeb.0
Keep-Alive: timeout=15, max=95
Connection: Keep-Alive
Transfer-Encoding: chunked
Content-Type: text/css

SOLUTION

When I disable mod_rewrite for PHP:

<IfModule mod_expires.c>
  # Enable expirations.
  ExpiresActive On
  # Cache all files for 2 weeks after access (A).
  ExpiresDefault A1209600
  # Do not cache dynamically generated pages.
  ExpiresByType text/html A1

 <FilesMatch "\.(php)$">
 ExpiresActive Off
 </FilesMatch>

</IfModule>

I get the following correct headers:

HTTP/1.x 200 OK
Date: Thu, 09 Oct 2008 22:17:34 GMT
Server: Apache/1.3.33 (Debian GNU/Linux) FrontPage/5.0.2.2635 mod_ssl/2.8.22 OpenSSL/0.9.7e
Cache-Control: must-revalidate
Content-Encoding: gzip
Etag: "651e2d539da48f303bbb3b37717ca3f8"
Expires: Sun, 19 Nov 1978 05:00:00 GMT
X-Powered-By: PHP/5.2.5-0.dotdeb.0
Last-Modified: Thu, 09 Oct 2008 22:15:54 GMT
Keep-Alive: timeout=15, max=100
Connection: Keep-Alive
Transfer-Encoding: chunked
Content-Type: text/html; charset=utf-8