Bug in Google Pagespeed?

Question

My site in Google Pagespeed gives 84 points. It says I can improve by adding browser cache headers. When I do this (Expires, E-Tag, ...) I get only 81 points and it still says I should add browser caching headers although it says content IS cached (5 Minutes).

I don't understand why it lowers the rating although I implemented the suggested fixes.

Why is this or what might I be doing wrong?

Answer 1

Google Page Speed likes to see files cached for a week or more. If you want the points, you could increase the cache time to have a max-age of 604800.