Whenever I read unread posts in a thread (the ones with the yellow folder), they're still marked unread for the duration of my stay. In the forum, the thread itself is marked as read (with a white folder). All the counters work fine too. It's just that inside threads, no post is ever marked unread untill I log off and log back on.
I'm running Mozilla 1.7.2 under FreeBSD/amd64 5.3-BETA6. I have tried the cookie reset, as well as clearing my browser cache. Mozilla 1.7.2 under WinXP SP2 works just fine.
This has me really puzzled, as I'm having a similar problem (except in reverse - new threads aren't marked at all) at another php-based forum. Seeing as how php is a server-side language, it leads me to think that it's a cookie issue, but it certainly manifests itself peculiarly!
"Power without wisdom is terrifying. Wisdom without power is pathetic."
-- Jay Wiseman
"You cannot enjoy success while dead."
-- Colonel Akula