By default the avatars are turned off. One must be a registered user to be able to turn them on. Here's how to do it:

Click “LOGIN”

Then fill in the following fields with your Username and Password.

Next click on the “PROFILE” tab

Immediately followed by “MODIFY PROFILE” and “Look and Layout:

Scroll down and uncheck the box next to “Don't show users' avatars.

Lastly, continue scrolling down and click “Change profile”.