Arduino LCD shows only black boxes

Question

I've hooked up my Arduino on this LCD, and after running the following code, all I see is a row with black boxes and another one empty.

//LiquidCrystal d(RS, E, D4, D5, D6, D7);
LiquidCrystal lcd(0, 1, 2, 3, 4, 5);

void setup() {                
     lcd.begin(16, 2);
     lcd.print("hello, world!");
}

void loop() {
     lcd.print("hello, world!");       
}

Wiring:

(The UTP cable is used just for the data lines :-)

Actual wiring photos: (sorry for the total klutz in the wiring, I had limited solid-core wires so I had to use these scrap ones)

Answer 1

The problem was that the R/W pin on the LCD was left floating, after I connected it to GND, I started working :)