Electronic – Arduino LCD not working

I'm getting started with LCD projects for Arduino, but for some reason, the LCD won't display characters.

I'm using this tutorial from the Arduino website, and this LCD with an Uno R3 board. This is the circuit diagram of my setup:

^{simulate this circuit – Schematic created using CircuitLab}

I don't have any formal eduction in EE (yet), but I think that the issue may be that where the tutorial's diagram shows the LCD's first two pins as being Vss and Vcc, the actual pins on the LCD are marked Gnd and VDD, respectively.

The code I'm using is essentially the same as that provided on the tutorial page:

// include the library code:
#include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  // set up the LCD's number of columns and rows: 
  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.print("hello, world!");
}

void loop() {
  // set the cursor to column 0, line 1
  // (note: line 1 is the second row, since counting begins with 0):
  lcd.setCursor(0, 1);
  // print the number of seconds since reset:
  lcd.print(millis()/1000);
}

It should display "hello, world!" on the LCD. However, when I power up the circuit, the display's backlight turns on, but no text appears. Around 3 seconds after powering up, all of the LCD's characters flash full white (the screen displays white-on-blue) for a fraction of a second, before returning to a blank, backlit screen indefinitely. Turning the potentiometer does nothing, although having it set to less than 10k ohms for any more than 5 seconds causes the chip underneath the display to overheat (I already burned out one display this way by setting the pot to about 5k ohms without noticing the damage being done).

Is this a common issue? Is there a solution, or an explanation for why this happens (a dud display)?