I tried both the WebServer and UdpNtpClient examples. Both work great on 1.0.3, but both hang with 1.0.4. I'm running on Linux 64 bit, if that matters.
Admittedly, I'm using an older hand-built Ethernet shield with Arduino Uno, and a Wiznet 812 module with Teensy. I just ordered an official/genuine R3 Ethernet Shield, so when that arrives I can try pairing it with my Uno (which is a genuine Arduino Uno, not a clone).