First off DALnet did not go under. It is alive and well, but the "Random dalnet server" link 'went under'. You need to use a specific link found at
www.dal.net. Secondly, do you have a router. You mentioned you do not have another firewall, but what about a router. Or do you go through a proxy maybe? You also could have anti-virus software that runs as a firewall that you are unaware of as well.