the ircd listens on 6667 and 7000 for regular connections, 6668 and 6697 for ssl connections.

Try connecting on 6667. If that doesn't work, try connecting on 7000. If that doesn't work, check out http://www.mirc.co.uk/ssl.html and try to grab openssl and drop the required dll's into mirc's directory. When connecting on ssl, prefix the port number with a "+" ... so you'd say "/server irc.gotwoot.net +6697" instead of "/server irc.gotwoot.net 6667".