<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>404 Not Found</title>
</head><body>
<h1>Not Found</h1>
<p>The requested URL /board/post_thanks.php was not found on this server.</p>
</body></html>

в смысле "кнопка СПС чёй-то не фурычит... и на Хроме, и на Лисе...