I'm using rails with nginx/passenger.

If I set up the expire http header of a css file to 1 year, if I modify that file, will it be ignored by the browser (ie, it will not request the new version)?

Given that Rails adds a different timestamps to each asset such as foo.css?1270165626 every time I restart the server?

That's the config I use right now (nginx/passenger):

    location ~* \.(ico|css|js|gif|jpe?g|png)(\?[0-9]+)?$ {
            expires max;
            break;
    }