OK, the way I see it is like this.
There are two avatars cause the forum/topic list has two elements that use an avatar.
1. the avatar from the poster of the topic, this avatar is there with the topic title.
2. there is in the freshness an avatar displayed for the reply poster.
In between the topic title and topic freshness there is an element that handles reply, post and/or voice count.
This makes three elements inside this forum list, two with an avatar, hence two avatars.
The list itself is situated in an UL (unordered list in a bbpress php file called loop-single-reply.php).
This ul has three LI (list) elements inside it, the first topic-title, second topic-count, and third topic-freshness.
btw, you have a cache plugin that prevents s to check your CSS in chrome etc.
This line of code will put the avatars where they need to be, you just add this to your themes CSS file, and remove the display:none from your .avatar CSS.
#bbpress-forums li.bbp-body ul.topic {
border-top: 1px solid #eee;
overflow: hidden;
padding: 8px;
float: left;
width: 100%;
}
Here is how it looked for me after adding this.
good luck
Peter Hamilton