Well this part *Message fields* is easy. You can find that in your lang/lang-english folder. As to the other part. I would just look for it in the various folders. And when you find it just delete that part of the script. FYI I dont know how you added it to your page but it is so far down at the bottom That you cant even click the sign guestbook part.
Ok instead of the language pack on your pc is it installed in the poll?? Just taking wild guesses here. Are your permissions set correctly? And actually it looks oriental to me. The font on the poll now.