There is no reason why a page should not update immediately if you force your browser to refresh from the domain (control-refresh in IE and shift-refresh in Netscape). Remember the transparent proxy is not the only place where caching is done. Copies are saved in your own computer's cache for quick reference, and there may be any number of cache operations at any point in the path from the customer to that site's server.
If you updated your site, but still cant see it updated, then its most probably your computer cache is the refreshed you just need to please (ctrl +f5) or need to delete your internet cache ,history and cookies.
After doing this your pages wil be showing updated immediately.
