Edit mobile style ... in the "forumhome_forumbit_level1_post" and "forumhome_forumbit_level1_post" templates
Find...
HTML Code:
<img src="{vb:stylevar imgdir_statusicon}/{vb:raw forum.imageprefix}forum_{vb:raw forum.statusicon}-16.png" class="forumicon ui-li-icon" id="forum_statusicon_{vb:raw forum.forumid}" alt="" />
Edit it to
HTML Code:
<img src="{vb:stylevar imgdir_statusicon}/forum_{vb:raw forum.statusicon}-16.png" class="forumicon ui-li-icon" id="forum_statusicon_{vb:raw forum.forumid}" alt="" />