this is due to the recent and ongoing attacks on DALnet, you cant use ramdom DALnet server, but need to use specific server, ie: /server liberty.dal.net and specifying the port helps. See http://www.irchelp.org/irchelp/networks/servers/dalnet.html
as suggested in another area of this board.
With many servers down, weekends are VERY hard to get onto DALnet, be patient and keep trying the ones listed at DAlnet's homepage (www.dal.net
) Note that twisted, which is mentioned on the url i gave above, has been delinked and wont work.