If directly opening a post from the main page (not as a new tab - but with a simple click) and afterwards using Firefox’, Seamonkey’s (the Mozilla family) Back-button, you end up at the top of the page. If you were already down at the lower part of the main page, it’s boring to scroll down again to locate the last post...

There was a short thread in the German 1.x forum, and I’m using the fix since March 2008 in 1.7.3-1.7.5 without any complaints from my users and I guess it worked also for JED (who suggested the fix; his forum contains well over 200000 posts).

The fix in 1.7 was (adding below the first include [line 27] to forum.php, mix.php, board.php):

include("inc.php");
header("Cache-Control: public, max-age=900");