Awful Cache - Proxy Servers
 

We have upgraded to VB3. So far so good. The problem we are facing for the moment is horrible Cache-Proxy servers. I have studied "no cache" header tags, PHP no cache and expiry settings and applied them to our site's code but it seems that non of them is effective. The only "bullet proof" ( ;) ) way seems to be a long random URL that does not let the cache or proxy server to do their horrible job caching private messages and forums or letting other users to have access to another member's account.
What I do not understand is: Why VB cookies are not being rechecked while letting people to access private messages or forums. Is it going to be effective? Is everybody browsing the board with cookies? If "Yes" why doesn't it stop cache servers?
I was wondering if someone here could come up with a solution to add a random string to the private message and forums. This way cache - proxy servers are bypassed and no one gets wrong information.
I would really appreciate you comments on this issue. How can we solve this problem permanently :(
Best regards

It might be an option to somehow always use the sessionhash...

Thank you for your comment Colin. It is a good idea but how to do it? Is it going to be as easy as adding sessionhash to the links? What would happen if users enter the URL in their browser?