<td class="profilright"><input type="text" name="emailaddress" style="width: 200px" size="20" maxlength="255"></td>

<td class="profilright"><input type="text" name="emailaddress" style="width: 200px" size="20" maxlength="100"></td>

<td class="profilright"><input type="text" name="emailaddress" style="width: 200px" size="20" maxlength="255" onblur="verify_register(this);" />
<span id="verify_emailaddress"></span></td>

<td class="profilright"><input type="text" name="emailaddress" style="width: 200px" size="20" maxlength="100" onblur="verify_register(this);" />
<span id="verify_emailaddress"></span></td>

if ($fm->input['useravatar'] != '' && (!preg_match("#^[A-Za-z0-9-_]{1,}\.[A-Za-z]{3,4}$#is",$fm->input['useravatar']) || !file_exists('im/avatars/'.$fm->input['useravatar']))) {

и замените её строкой:
CODE:
if ($fm->input['useravatar'] != '' && (!preg_match("#^[A-Za-z0-9-_]{1,64}\.[A-Za-z]{3,4}$#is",$fm->input['useravatar']) || !file_exists('im/avatars/'.$fm->input['useravatar']))) {

include('language/'.DEF_LANG.'/lang_tz.php');
$fm->input['timedifference'] = (isset($tz[$fm->input['timedifference']])) ? $fm->input['timedifference']:0;

if ($fm->exbb['wordcensor'] === TRUE && $fm->bads_filter($fm->input['signature'],0) === TRUE) {
$fm->_Message($fm->LANG['Registration'],$fm->LANG['NoProfanity']);
}

$siglines = explode("\n",$fm->input['signature']);
if (count($siglines) > $fm->exbb['max_sig_lin'] || strlen($fm->input['signature']) > $fm->exbb['max_sig_chars']) {
$fm->_Message($fm->LANG['Registration'],sprintf($fm->LANG['SigOptions'],$fm->exbb['max_sig_lin'],$fm->exbb['max_sig_chars']));
}

if (!preg_match("#^[A-Za-z0-9-_]{1,}\.[A-Za-z]{3,4}$#is",$fm->input['useravatar']) || !file_exists('im/avatars/'.$fm->input['useravatar'])) {
$fm->input['useravatar'] = 'noavatar.gif';
}
} else {
$fm->input['homepage'] = $fm->input['icqnumber'] = $fm->input['aolname'] = '';
$fm->input['location'] = $fm->input['interests'] = $fm->input['signature'] = '';
$fm->input['timedifference'] = 0;
$fm->input['useravatar'] = 'noavatar.gif';
}
return;
}

?>