Arduino Ethernet shield and SD card

Hi there!
here goes:

void setup()
{
Serial.begin(9600);
pinMode(10, OUTPUT);
digitalWrite(10, HIGH); //so that SPI will work
pinMode(53, OUTPUT); //so that SPI will work
pinMode(4, OUTPUT);
delay(100); //some time to stabilize outputs

if (!SD.begin(4))
{
Serial.println("SD card failed or not present");.
return;
}
...
}

Thanks!