I got this to work in the PostBit template by doing the following:
Look for the following code:
HTML Code:
<div class="userinfo<vb:if condition="!$show['avatar']">_noavatar</vb:if>">
<div class="contact">
<vb:if condition="$show['avatar']">
<a class="postuseravatarlink" href="{vb:link member, {vb:raw post}}" title="{vb:rawphrase {vb:raw post['onlinestatusphrase']}, {vb:raw post.username}}">
<vb:if condition="$post.avatarurl">
<img src="{vb:raw post.avatarurl}" alt="{vb:rawphrase xs_avatar, {vb:raw post.username}}" />
<vb:else />
<img src="{vb:stylevar imgdir_misc}/unknown.gif" />
</vb:if>
</a>
Insert the following code right after the last </a> tag shown in the code above:
HTML Code:
<vb:else />
<a class="postuseravatarlink" href="{vb:link member, {vb:raw post}}" title="{vb:rawphrase {vb:raw post['onlinestatusphrase']}, {vb:raw post.username}}">
<img src="{vb:raw vboptions.noavatar_url}" alt="{vb:raw post.username} Don't Avatar" border="0" />
</a>