pycs.net is run from a lounge in NewZealand?, and connects to the Internet via a 128K DSL connection. Unfortunately, part of the deal with the DSL network here is that you can't get a static IP. As such, the DNS record for www.pycs.net changes every time the DSL disconnects, i.e. fairly often. There's a delay involved each time this happens.
See PycsFuture for info on what is being done to fix this.