rbezan:
Yes i have:
the 9V battery was actualy 3,15V with load (9,34 without load)
so i tried with a power suply:
settings on 9V :
with the load 3,30 V (without load: 10,47V)load - (connected to the arduino UNO and ethernet shield)
And there you have answered your own question. The current needed by your project is way beyond what the batteries or the power supply can deliver.
Paul