Css and js gzip Compression

hi.

I use apache with passenger and I want to enable the gzip Compression.

I use the apache sample configuration
http://httpd.apache.org/docs/2.0/mod/mod_deflate.html with following
filters
AddOutputFilterByType DEFLATE text/html text/plain text/xml text/css
text/javascript

The compression works fine if I include the .js or .css files in this
way.

But if I use the javascript_include_tag or the stylesheet_link_tag the
compression doesn’t work.

Why does this not work?

thanks,
Michael