I think it the problem lies in the concept behind those listings. If you check their list, you'll see that they are based on EMAIL addresses once (or twice?) used to send spam, and they block the IP that was associated to that email when it was identified as spammer. 

The problem is that rarely a spammer will use a static or dedicated IP!!!... More often than not, they'll go to LAN houses or Cybercafes, anywhere where they can pay per use to access internet, and send spam using a public and free email account, (like Gmail or hotmail, as I saw most of the ones listed there), until this account gets spotted and blocked. 

And the biggest problem is that the same IP is issued later to an honest user, as those are issued dynamically (temporarily) by the internet access provider when you connect to the internet, a different one each time!

I believe that it's exactly what happened to me, the IP I was using and that got blocked was indeed listed there, but in connection to 4 or 5 different emails (gmail and hotmail). I have no control over the IP I'll using every day when I turn on the internet... And today I was issued a 'bad' one, among the millions the internet provider has registered to them...

So, maybe (I don't know if it's possible), you could find a way to use the same database but NOT block the IP, and block the email instead?

I mean, I was connected using MY email, which is the same as the Admin, and still got blocked because the IP was linked to 5 different spotted spammers??? It doesn't seem too efficient, does it? :)

i deactivated the plugin

i dont want to risk members or people who want to sign up getting blocked...

Thank you for the input Ben. I agree, it's hard to create the perfect antispam software. At another website I have, not even recaptcha would stop them from spamming aggressively... (they used the forms to send their messages, and the forms had ReCaptcha on them. Most part of the time I can't figure out what the words/characters are!!! lol...)

Maybe the best for my website now is to approve each member and not use any anti-spam plugin for now. IP blocking definitely won't work for me, because of the dynamic IP assignment I mentioned before...

But nope, my computer has not been hacked. I've been using computers since Apple IIe and PC 286... :)  (yeah, unfortunately, that old! lol) I have a paid anti-virus and I often run a reliable online malware scan just to be sure. I haven't clicked unknown links since forever and I never open any attached file, even from people I know well, before having it scanned. They are good people, but might not be computer 'proficient'.. :) 

I checked the antispam db and my email was not there. And the IP range by my internet access provider, when listed, was associated with other email addresses (none of them mine!)

So, as my website is new, I've decided not to use any antispam for now, if based on IP. I have other open source websites too, and I never had any problem accessing them before. Mostly because they scan whatever the person POSTS there, not where they are accessing from, I guess...

Well, if the traffic to the website increases greatly, I might have to review this policy, but I believe it'll work for now (members by approval only). 

Thank you all for your help and input and... HAPPY NEW YEAR!!!