Using forum icons with redirection forums

So I have a problem with my forum, I'm using the forum icons hook to allow custom forum icons for each forum however if I make re-direction forums they can't have their images changed separately does anyone know why?

They can't have what images changed separately?

f_redirect.png this image that is the small image next to the forum name like shown below on Nulled:
http://i.imgur.com/OffvfhO.png


This is easy to do, but for redirection forums I do not know how to change the image.