Prolem with Cache-Control:max-age http header

Hello

It seems that safari do not take into account Cache-Control:max-age=31536000 http header.
Sending this header to the browser I would expect that safari will not ask the server for these resources before current date + one year.
It's the way IE and FireFox are working but safari is asking the server for these resources every time my html page is loaded (see http requests below).
Server returns a 304 status to indicate that the resource is not modified.

Does somebody have an idea about this strange behaviour?
I'm surprise that Safari do not respect RFC specifications.
Is there a settings to enable Cache-Control ?
Perhaps I forgot safari's specific headers..

Thanks

+GET 786 +
GET /xtend/htmrsrc/LIB/XtendAjaxScripts.js HTTP/1.1
...

+RESP 786 +
HTTP/1.1 200 OK
Server: Apache-Coyote/1.1
Last-Modified: Wed, 15 Oct 2008 13:25:24 GMT
*Cache-Control: PUBLIC, max-age=31536000, must-revalidate*
*Expires: Thu, 05 Nov 2009 13:09:10 GMT*
Content-Type: application/x-javascript;utf-8
Content-Length: 2856
Date: Wed, 05 Nov 2008 13:09:10 GMT

+GET 799 +
GET /xtend/htmrsrc/LIB/XtendAjax.js HTTP/1.1
If-Modified-Since: Fri, 24 Oct 2008 07:59:24 GMT
...

+RESP 799 +
HTTP/1.1 304 Not modifed
Server: Apache-Coyote/1.1
Date: Wed, 05 Nov 2008 13:11:19 GMT