DNS pool isn't an error message, so don't worry about that message. If you are timing out connecting, it could be that you're trying to connect to a server that's not working well, or using a port that isn't working well on that server, or have some issues with your settings. It's also possible that your ISP blocks IRC connections.
Please provide more details so we can help. This such as what server you're connecting to, do you use a router and/or firewall, what OS, what mIRC version, any scripts you have, and any additional information you can give that might narrow down the problem. Also, let us know if you can connect to other networks besides the one you're trying to connect to. Try the main networks like efnet or undernet.