If you’re having DNS issues with irc.p44.org, flush your DNS. Under Windows, go Start -> Run -> ipconfig /flushdns. A window will pop up for a split second and then disappear. It should then work. :)

And for future reference if this kinda thing happens again, try using irc.us.p44.org or irc.eu.p44.org. The Java chat has been updated to have these as backup servers in the case that you can’t resolve irc.p44.org. :)