Hello,
I've configured my IIS 6.0 load-balanced website to have empty ETag headers, per what YSlow recommends for load-balanced websites.
Both before AND after I configued this empty ETag header, I got all images being cached on the client side, but with primed cache it was still checking for new versions on the server and returning a 304 [Not Modified] response.
As mentioned above, I saw this problem [using Firebug 'Net' tab], then configured the empty ETag, but the problem remains there.
This causes the page to have a lag with rendering the page, as it waits for all images to return the 304...
I have now a header that looks like this:
Cache-Control: max-age=0
Just to prevent default questions: I've configured the cache for my images domain to 60 days.
Any idea how to force the images to be cached?