Board acting weird?

[Alturin]

Every subforum is marked as having unread replies, but when I click the icon is sais:

No unread topics found since your last visit. Click here to try all unread topics.

Even when the RSS feed says there are.
Clicking on the subforum (e.g., going to the page that shows all threads in the subforum) removes the mark.

Not sure why this happens, if there's anything I can do to help to fix this I'm happy to help.

Alturin @
Windows XP SP2
Firefox 2.0.0.3