Problems in connecting the arduino to internet using Wifi-shield

hi evening
my problem is, wifi shield not detect wifi network in 2 security modes (open , wep), im using connectivity in laptop feed arduino internet access wirelessly, arduino board  connected same laptop, , strange point that, ipad can detect , link wireless network without problems in both cases (open , wep secured), arduino scanning , detects 0 networks.
im using  scanning code arduino website... in advance 

code: [select]

#include <spi.h>
#include <wifi.h>

void setup() {
  // initialize serial , wait port open:
  serial.begin(9600);
  while(!serial) ;

  // attempt connect using wep encryption:
  serial.println("initializing wifi...");
  printmacaddress();

  // scan existing networks:
  serial.println("scanning available networks...");
  listnetworks();
}

void loop() {
  delay(10000);
  // scan existing networks:
  serial.println("scanning available networks...");
  listnetworks();
  serial.print("\n");
}

void printmacaddress() {
  // mac address of wifi shield
  byte mac[6];                   

  // print mac address:
  wifi.macaddress(mac);
  serial.print("mac: ");
  serial.print(mac[5],hex);
  serial.print(":");
  serial.print(mac[4],hex);
  serial.print(":");
  serial.print(mac[3],hex);
  serial.print(":");
  serial.print(mac[2],hex);
  serial.print(":");
  serial.print(mac[1],hex);
  serial.print(":");
  serial.println(mac[0],hex);
}

void listnetworks() {
  // scan nearby networks:
  serial.println("** scan networks **");
  byte numssid = wifi.scannetworks();

  // print list of networks seen:
  serial.print("number of available networks:");
  serial.println(numssid);

  // print network number , name each network found:
  (int thisnet = 0; thisnet<numssid; thisnet++) {
    serial.print(thisnet);
    serial.print(") ");
    serial.print(wifi.ssid(thisnet));
    serial.print("\tsignal: ");
    serial.print(wifi.rssi(thisnet));
    serial.print(" dbm");
    serial.print("\tencryption: ");
    serial.println(wifi.encryptiontype(thisnet));
  }
}

i don't know got code, have tried of examples included ide? there 3 examples, each using different security method.
connectnoencryption
connectwithwep
connectwithwpa

have tested shield see if firmware current?

Arduino Forum > Using Arduino > Networking, Protocols, and Devices (Moderator: fabioc84) > Problems in connecting the arduino to internet using Wifi-shield

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