"Caching policy" skin extension property is not taken into account (at least in Firefox)

• create a jsx
  • Use this extension: current page
  • Parse content: No
  • Caching policy: long
• reload the page several times

-> with Firefox network module I see that http://127.0.0.1:8080/xwiki/bin/jsx/Test/JSX?language=en is fully reloaded every time (same for all the other standard jsx)