Buenas, no puedo poner ninguna imagen, 1 porque nose 2 el pc me va fatal para bajar programas, te dejo el contenido de newthread:
<html>
<head>
<title>{$lang->newthread_in}</title>
{$headerinclude}
<script type="text/javascript" src="jscripts/post.js?ver=1400"></script>
</head>
<body>
{$header}
{$preview}
{$thread_errors}
{$attacherror}
<form action="newthread.php?fid={$fid}&processed=1" method="post" enctype="multipart/form-data" name="input">
<input type="hidden" name="my_post_key" value="{$mybb->post_code}" />
<table border="0" cellspacing="{$theme['borderwidth']}" cellpadding="{$theme['tablespace']}" class="tborder">
<tr>
<td class="thead" colspan="2"><strong>{$lang->post_new_thread}</strong></td>
</tr>
{$loginbox}
<tr>
<td class="trow2" width="20%"><strong>{$lang->thread_subject}</strong></td>
<td class="trow2">{$prefixselect}<input type="text" class="textbox" name="subject" size="40" maxlength="85" value="{$subject}" tabindex="1" /></td>
</tr>
{$posticons}
<tr>
<td class="trow2" valign="top"><strong>{$lang->your_message}</strong>{$smilieinserter}</td>
<td class="trow2">
<textarea name="message" id="message" rows="20" cols="70" tabindex="2">{$message}</textarea>
{$codebuttons}
{$multiquote_external}
</td>
</tr>
<tr>
<td class="trow1" valign="top"><strong>{$lang->post_options}</strong></td>
<td class="trow1"><span class="smalltext">
<label><input type="checkbox" class="checkbox" name="postoptions[signature]" value="1" tabindex="7"{$postoptionschecked['signature']} /> {$lang->options_sig}</label>
{$disablesmilies}</span></td>
</tr>
{$modoptions}
{$subscriptionmethod}
{$pollbox}
{$captcha}
</table>
{$attachbox}
<br />
<div style="text-align:center"><input type="submit" class="button" name="submit" value="{$lang->post_thread}" tabindex="4" accesskey="s" /> <input type="submit" class="button" name="previewpost" value="{$lang->preview_post}" tabindex="5" />{$savedraftbutton}</div>
<input type="hidden" name="action" value="do_newthread" />
<input type="hidden" name="posthash" value="{$posthash}" />
<input type="hidden" name="attachmentaid" value="" />
<input type="hidden" name="attachmentact" value="" />
<input type="hidden" name="quoted_ids" value="{$quoted_ids}" />
<input type="hidden" name="tid" value="{$tid}" />
{$editdraftpid}
</form>
{$forumrules}
{$footer}
</body>
</html>
Edito: esta es la imagen, y ese el problema.