Tal vez sea porque en la viste previa la info + avatar de user aparece en horizontal y al publicar en vertical. Acá te dejo el posbit:

Código:
{$ignore_bit}
<a name="pid{$post['pid']}" id="pid{$post['pid']}"></a>
<table border="0" cellspacing="{$theme['borderwidth']}" cellpadding="{$theme['tablespace']}" class="tborder" style="{$post_extra_style} {$post_visibility}" id="post_{$post['pid']}">
    <tbody>
        <tr>
            <td class="tcat">
                <div class="float_left smalltext">
                    {$post['postdate']}, {$post['posttime']} <span id="edited_by_{$post['pid']}">{$post['editedmsg']}</span>
                </div>
                {$post['posturl']}
            </td>
        </tr>

        <tr>
            <td class="trow1 {$unapproved_shade}">
                <table cellspacing="0" cellpadding="0" border="0" style="width: 100%;">
                    <tr>
                        <td class="post_avatar" width="1" style="{$post['avatar_padding']}">
                            {$post['useravatar']}
                        </td>
                        <td class="post_author">
                            <strong><span class="largetext">{$post['profilelink']}</span></strong> {$post['onlinestatus']}<br />
                            <span class="smalltext">
                                {$post['usertitle']}<br />
                                {$post['userstars']}
                                {$post['groupimage']}
                            </span>
                        </td>
                        <td class="smalltext post_author_info" width="165">
                            {$post['user_details']}{$post['suscriber']}<!-- Achiviement_PIP -->{$post['points_pip']}<!-- /Achiviement_PIP -->
                        </td>
                    </tr>
                </table>
            </td>
        </tr>

        <tr>
            <td class="trow2 post_content {$unapproved_shade}">
                <span class="smalltext"><strong>{$post['icon']}{$post['subject']} {$post['subject_extra']}</strong></span>

                <div class="post_body" id="pid_{$post['pid']}">
                    {$post['message']}
                </div>
                {$post['attachments']}
                {$post['signature']}

                <div class="post_meta" id="post_meta_{$post['pid']}">
                {$post['iplogged']}
                </div>
            </td>
        </tr>

        <tr>
            <td class="trow1 post_buttons {$unapproved_shade}">
                <div class="author_buttons float_left">
                    {$post['button_email']}{$post['button_pm']}{$post['button_www']}{$post['button_find']}{$post['button_rep']}
                </div>
                <div class="post_management_buttons float_right">{$post['button_edit']}{$post['button_quickdelete']}{$post['button_quote']}{$post['thanks']}{$post['button_multiquote']}{$post['button_report']}{$post['button_warn']}{$post['button_reply_pm']}{$post['button_replyall_pm']}{$post['button_forward_pm']}{$post['button_delete_pm']}
                </div>
            </td>
        </tr>{$post['thxdsp_inline']}<!-- PointsInPosts -->{$post['pip']}<!-- /PointsInPosts -->
    </tbody>
</table>{$post['thxdsp_outline']}

P/D: No uso ese plugin, solo es editado de plantilla que saque de: PostBit Perfil No me acuerdo si era ese específicamente pero es la misma temática
Seguro es un error de tu navegador o de alguno de los plugins porque en ese codigo no veo nada mal
:)
Mi navegador no tiene la culpa de nada, probe en Firefox e IE y sigue igual. uso chrome Sad