Just cleared the cache. Will see what happens over the next couple of hours as I come and go from here.
No issues at all since my post yesterday either on my Win 7 or XP machines.
Will post back though if issues occur again.
No complaints yet? Seems like this could be marked as fixed then.
If someone’s interested I’ll give a small summary of the problem; maybe some other developer runs in to the same issue.
The problem was that a 301 permanent redirect (from /home/activity to /home/forum) was saved in the browser cache somehow. This probably happened because the user is redirected away from /home/activity if not logged in. But I don’t know exactly how this happened, since the software is supposed to use temporary redirects and not 301’s.
Anyway, the workaround was to turn off browser caching of dynamic content entirely, something like:
header('Expires: Mon, 26 Jul 1997 05:00:00 GMT');
header('Last-Modified: '.gmdate("D, d M Y H:i:s") . " GMT");
header('Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0');
And then asking everyone to clear their cache, since the erring redirect was saved in the cache infinitely (at least Firefox does this).
Turning off the cache shouldn’t be a problem, since there is not much to gain by caching dynamic content anyway. This doesn’t affect images and scripts and stuff, so the impact on bandwidth is negligible.
Two days now without issue.