I've shut down the IRC network in 2011. You can use freenode, efnet, or any of the other 1,500+ public networks.
This plugin works with 1.2 just fine. I am still using this on a huge web site. I have not heard from the developer of this app in 6+ months, consider it abandoned. That said, Jaxel made a IRC integration plugin - if this one doesn't work for you, you can always try that one.
I hope that answers your questions.