Change "unread" behaviour of forum with subforums?

[kyan]

Hello,

In our board we have several forums that have subforums. For example we have this layout:

Board Home
  Italian Cars
    Fiat 
    Lancia
    Alfa Romeo

and both forum levels Italian Cars and Fiat/Lancia/Alfa Romeo contain threads (Act as Forum = Yes).

When there is a new post in a subforum e.g. Fiat the icon of the parent forum Italian Cars changes to "unread". This misleads the user in thinking that there are unread posts inside Italian Cars while there are new posts only inside Fiat.

Is there a way to change this behaviour so that when a post is made in the subforum (Fiat) only the subforum itself gets an "unread" icon
and not its container (Italian Cars)?

I searched the vBulletin general options and individual forum options but I couldn't find an option that seems to handle this. I found only the ones that control the "level" of subforums displayed. I asked how this can be done at VB.com but the answer was that there is no way to do this through options.

Has anyone else had this issue? Maybe there is a solution to this but I think that it would require code modifications, so if someone has done something about it and wants to share the solution, please do.

TIA.