Problem with unread posts in subforums

[HexImaL]

Hi, guys, I have a rather strange problem, will be glad if you point me to threads discussing this or propose a solution here.

Basically, when I read all new posts and go back to the front page of the forum, the forum still shows there are new topics in the subforums, although there aren't any. This happens in sub forums which have a sub forum of their own. As soon as I enter the subforum and get back to the front page, the forum shows no new posts (that's without opening any thread in the subforum, just opening the sub forum).

Any ideas how to fix this? I suppose it's a cookie issue, but you are the specialists.

edit: Not sure why my post was moved here, since this shouldn't be something that requires scripting help; if it does, it's an SMF bug.

[HexImaL]

Bump.