[moved on arduino due forum] Wifi-Shield problems with Arduino Due.

Hi to all,
I tried my wifi-shield on a Arduino Due board.
The shield correctly works on Arduino Uno (connecting to my Lan, receiving and sending on internet etc.)
but it not property works on Arduino Due.
I tried some examples from tutorials to understad:
1) when I try ScanNetworks it correcttly find my Lan.
2) when I try WiFiWebClient it not works:
On the first monitor it answer "no wifi shield" and it give me the same answer also resetting the board.
After some resets it try to connect, but without goal.
Only one time it connected to the Lan, and to server (www.google.com), but it not gave any http request answer.
I use:
- Arduino due from programming port (it correctly works with many scratches)
- wifi shield R3 with firmware v.1.1.0
- an external power suply of 12V 4A (center positive)
I don't know why the shield doesn't works...
tank you for any suggestion.