NOTE: Instead of replying, you should create a new message so we keep the different topics separated.
To answer your question, in most cases, this error message means that someone with a similar IP address was banned and they included a range of IP addresses that happens to include yours. The best thing to do is go to the network's website and email them. You can use Google to find their website. For example, searching for Undernet will tell you that their website is
www.undernet.org . Their website should include contact information. Just email them and tell them about your problem and give them your IP address and they should be able to help you.
