Avatars have been intentionally disabled. Avatars tend to add unnecessary clutter to the forums...we'd like to keep the forums as clean as possible.
I disagree. I'm an admin on a very large computer-related forum (currently 150,000 registered members and about 25 million posts), and having avatars really helps in recognizing your fellow members. We have set some rules of course, we limit the size of the avatars to 60x60 pixels, it should be max 100kb and it shouldn't be too flashy. Furthermore, every user can choose for himself if avatars are visible or not, so those who don't want to see it can easily disable it.