HTTP 304 Not Modified

http 304

[Ragwin]

I'm getting 304 Not Modified on 3 web pages. Don't understand. They have had 95% of the content changed, how can they not be modified?

[lucy24]

Have you excluded your ISP as culprit?

[Ragwin]

Other pages I've changed in the same way are redirtected, why would these be any different?

[tangor]

This 304 is coming from ... where? Mentioned redirects, are these 301s?

[Ragwin]

304 coming from the source page of the redirect.

[Ragwin]

This one redirects ok:

Redirect 301 /Horse%20Tack%20ItoZ.html http://www.example.com/drupal/content/horse-tack-supply-stores-i-z

This one returns a 304:

Redirect 301 /Quarter%20Horse%20Sales%20And%20Breeders%20A%20To%20J.html http://www.example.com/drupal/content/quarter-horse-sales-breeders-location-a-to-j

[edited by: phranque at 8:08 am (utc) on Mar 10, 2014]
[edit reason] Please Use example.com [webmasterworld.com] [/edit]

[lucy24]

Is it too late to change your URLs? Different thread.

About the ISP: Certain providers, naming no names, are notorious for caching material long past its expiration date. (Also for caching things that should never have been cached in the first place, but that's a different issue.) So your request never even reaches the server; the 304 comes from the ISP. Try fetching the page from a different computer using a different ISP. That's in addition to, not instead of, the usual empty-the-cache and force-a-refresh angles.