I am wondering if I have to do some initialization to the w5100 shield. I tried variations of the code, but to no avail. The EthernetShield page (http://arduino.cc/en/Main/ArduinoEthernetShield) states "The solder jumper marked "INT" can be connected to allow the Arduino board to receive interrupt-driven notification of events from the W5100, but this is not supported by the Ethernet library."
Does that mean I have to rewrite the library, or does it mean I have to code around the library (e.g. not using the "attachInterrupt" functions)? Or is there another way?