I don't really understand your system of punishment. I'm a newbie here but I've been a member of several forums for almost 5 years. Flooding the abusive member with pop-ups and also hanging his browser? FTW. It's not the proper way of being organized. I suggest you have a punishment system like these:
0% warn level: Nothing wrong here, you've got a clean slate, and you should be proud of it!
10~20% warn level: No suspension here unless you've committed a major offense.
30~40% warn level: Here is when the posting suspensions start, a 1 day posting suspension is issued, but may be more depending on level of offense.
50~80% warn level: Posting suspensions continue, you will have your posting privileges taken away from you for 1~7 days, again, based on level of offense.
90~100% warn level: Posting suspensions get harsher, you will receive a long suspension when at 90%, possibly for about 1 whole week, and will face an account suspension and a IP ban when you reach 100%.
This was adopted from Dota Allstar forum. Here's the exact link:
http://forums.dota-allstars.com/index.php?showtopic=151644