you might have been very unlucky and tried to connect just during the 1min downtime of patching. The first time you log in, you might get a client crash due to the new sound engine, but this should only happen once, if it all. Aside from that I'm not aware of any problems installing und running client, aside from linux and apple users or winX, which I really can't help with.
Port and IP have not change and should still be set in the client, play.fonline-aop.net, port 4000 iirc