Spam. Please help me

Hello. I am the owner of www.tormented.tv . I am using version 2.4.3 of the guestbook software I have had my guestbook up for about a year now and have had very little issues with it. was able to get it matching my site beautifuly and have been very happy with it. I have however over the year had a few spam bots find it and place adds even tho i have links and stuff disabled they still post. Its not been a problem ..Just 1 or 2 a month but my site must be getting more hits because now i am getting over 20-30 a day! I installed the MOD today with hopes of getting this problem solved and within an hour of installing the MOD i had 2 spam post...So this is telling me that my spammer is human and not a bot right?
Is there a way to make another question mod but have it have a drop down menu with yes or no answer and have the wrong answer as the defult? If its a bot it seems that way would work more of the time.
Anyways if its a human using proxies how can i make it less attractive to the spammers? Is there a way to make it auto ban ANYONE that places a URL in the msg area ?
Theres gotta be something that can be done. Im going to end up having to either close the guestbook or make it a password and thats just dumb.
If anyone can help me PLEASE do so i would greatly apprecate your time
ToRmEnTeD

As I said in the other thread have a look at Lazarus. I added more anti spam layers as well as entry moderation. There is also URL limiting.