It's your cache. I see correctly the icons in the index, also in the subforums.
I tried clearing my cache and changing my theme. I can see them when I log out, it's just on my account.
did you try rebuild skin ?
How do you rebuild the skin?
I can clearly see icons in the linked forum, so it's a problem with your browser/system. Try with another.
As I stated in a post above, there is something wrong with my account. I can see it when I log out, it's only when I am logged in. I have tried using Chrome and Internet Explorer, but both to no avail.
I fixed the problem with several user/group/theme/code tweaks.