Images charged with 301 and 200 !

[claireve]

Hi everybody,
I have installed Avalanche Imagine Bundle and set up some thumbnails. Everything works fine..except the cache functionality.
Indeed, I want my images to be cached (for example for 2 weeks as in the documentation example). I also changed the config file of Apache as said in the documentation example. But when I go to my webpage in prod with my Avalanche thumbnails (where the cache is enabled) I can see with Firebug that my images are loaded with 301 (fine, that means there in cache) but also with 200. I don't understand what's happening ... and so my website is still slow..

Thank you very much for helping me

Here is my config

avalanche_imagine:
filters:
my_thumb:
type: thumbnail
options: { size: [195, 130], mode: outbound, quality: 100, format: png, cache_type: public, cache_expires: 2 weeks }

[design311]

According to the documentation:

Cache headers are set only for first request when image is generated.
To solve this issue you should add additional configuration for your web server.
Example for apache web server:

<IfModule mod_expires.c>
    <Directory "/path/to/web/media/cache">
        ExpiresActive On
        ExpiresDefault "access plus 2 weeks"
    </Directory>
</IfModule>