Thread Icons

[Breakers22]

First off my forum is wiiboost.com/forum. There is a test account if you need it username: test password: test123

I am trying to change the blue icons on the right of the forum categories... as you can see on the bottom of the forum, I tried to change it but it only changed the bottom images.

Any help??? When I right click the icons it doesn't recognize an image there.