gzip compressions with htaccess

gzip compressions with htaccess

I'm trying to speed up page load times by serving gzip compressed files
(such as js, css, imgs etc) from my server using the htaccess file but
it's not working. I'm using 1&1 servers which have gzip and zlib
installed.
Here is the code:
<ifModule mod_gzip.c>
mod_gzip_on Yes
mod_gzip_dechunk Yes
mod_gzip_item_include file \.(html?|txt|css|js|php|pl)$
mod_gzip_item_include handler ^cgi-script$
mod_gzip_item_include mime ^text/.*
mod_gzip_item_include mime ^application/x-javascript.*
mod_gzip_item_exclude mime ^image/.*
mod_gzip_item_exclude rspheader ^Content-Encoding:.*gzip.*
</ifModule>
I can see my browser accepts gzip encoding but it's not being served. I
can't see what I've done wrong here, have I written the code wrong?