Hello

The solution on this problem is to change line 213 in index.php from:
header('Cache-Control: public, max-age=300');
to:
header('Cache-Control: private, no-cache="set-cookie"');

I'm not convinced. With the code the browsers should cache the pages (for 300 seconds (5 minutes)). The IE was excluded from this solution because of problems as stated in the comment in front of the line #213 (#211 f.).

What the web browser SHOULD DO and what the web browser ACTUALLY DOES is two complete different things.

???

By doing this change, and this change only, the problem was solved.

We will see. The header was introduced, because the Firefox jumped not to the scroll position of the prior page when using the browsers back button without the header. On the other hand the MSIE stored not the folding state of the threads on the main page with this header. Thatswhy this browser was excluded from the header.

We have to check, if your solution is not only the solution for the IE but also not the introduction of a misbehavior in other browsers.

Unless the web server is very busy, there is not much need for cache. For the web sites I'm responsible for, web cache is not needed at all.

I strongly disagree [edit]with this generalised form[/edit]. There is not only the more or less busy server, there is on the visitors side also the device(s) with internet connections with restrictions in speed or in the available monthly data volume. It's i.e. simply unnecessary to serve the background images and the images of the icons on every request. The HTML with the perhaps changed content on the other hand should be actualised (at least) within a short time without loosing the information about the state of the pages.

It might be a part of the solution to store a few more informations about the state in the users browser on the server and in the browser (JavaScript's localStorage and sessionStorage).

Tschö, Auge