To help a friend am translating his problem here:
Before I was including in the .htaccess AddHandler application/x-httpd-php5s .php .js .css with the purpose that with the same PHP I could create the rules for Cache and Compression. What I did exactly was modify the auto_prepend_file in the php.ini file, pointing it to a PHP file and through there check the variable that is send by the browsers in the header $_SERVER["HTTP_IF_MODIFIED_SINCE"].
If the dates were different, I would answer with a header('HTTP/1.1 200 OK') and that would send the JS or CSS files compressed. If the dates were the same, then I would send a header('HTTP/1.1 304 Not Modified') and the browser did not have to download the JS or CSS files in questioned.
For some reason, the AddHandler application/x-httpd-php5s .php .js .css rule in the .htaccess stopped working
(I imagine for security reasons in the webhosting am in) and now the JS and CSS files are not been updated unless the user refreshes the webpage F5
The problem is that, since the CSS or JS files are not been updated the users do not know that they have to refresh the page to see the changes.
Is there another simpler way of doing the same procedure but without the AddHandler in .htaccess or a workaround for this.