I mean it does not make much sense to reload a session and it auto shows all the read posts as unread again. Or when I make a post myself and it shows up as unread no matter what I do (except manually mark ALL forums as read).
Maybe it is just a weird bug in this version, or maybe a combination bug between the 2 versions (xoops and cbb), I really dont know. I just know that my forums are halfway useless now, becuase all the forums/posts keep showing up as unread.
I'm guessing you have it coded to show new posts since your last login/session. So even if i read a post (even on your forum) It will still show up as unread. What I beleive other forum software does is tag each froum/topic you have actually viewed in the cookie. So that way it can decide which topics/forums to show as read or unread.