Ethernet Shield uploading problem!!

[system]

Hi all,

I have an an Arduino Ethernet Shield connected to an Arduino Uno, two days ago everything was okay.

However, I now cannot upload any code to the Arduino when the Ethernet Shield is connected.
This message appears: "avrdude: stk500_recv(): programmer is not responding"

Any one could help?

Many thanks in advance

[system]

I've had the same error on the NG and the Mega 2560 and realized that I had taken the jumper off of the EXT USB pins. Replaced the jumper and all was well.