Arduino Mega 2560 R3 ethernetshield

Dear,

I'm currently making an UDP communication with arduino and labvieuw.
When i use the arduino UNO, it works fine,
when i use the arduino Mega 2560 it doesn't work.
I'm using arduino 1.0.3 an ethernetshield with wiznet W5100 chip

The arduino failes with trying to get a IP, i'm using dhcp on it.
does someone know what the problem can be?

I seem to be on a mission because I keep asking people to try a different version other than Arduino 1.0.3

I've helped some people with some very strange problems by using another version and this sounds like one of those really strange problems.

I don't have a problem with any version after v1.0.

Now for my standard first question in this situation: Do you have a SD card in the shield's slot? If so, remove it for a test.

Ok i will try it without the SD card.
but also need the SD card (not jet porgrammed)
I will let the results know at wensday

You can use both together. Removing it was just for a test to insure the w5100 is working ok. This link shows how to initialize both to work together.