Transparent Proxy Issues

[NetNessie]

This may be a complete stab in the dark, I don't know an awful lot about this, hence why I'm asking.

A few ISP's in Australia use transparent proxies to "decrease loading times", what it is doing however is preventing these people from visiting my website, as they are being shown older pages that are cached, not the actual pages. This is a big pain with my blog for instance, as they are being shown posts from nearly a month back.

Are there any Apache settings I can fiddle around with, or maybe something I can throw into the HTTP response header, that will force the proxy to update its cache?

[sir_plague]

Try putting this in your HTML page's header. There's a similar method using PHP, but I can't remember the exact way to do it.

<meta http-equiv="Pragma" content="no-cache" />
<meta http-equiv="Expires" content="-1" />