I've noticed a person above this thread is having the same problem I am. I've tried putting resistor between the voltage supply (5v) but it's not helping.
I've actually got the LCD working about a week ago: I've just hooked the LCD driver in its appropriate pins (ground, 5v, and Rx pin). But now, whenever I hook the ground and voltage source, the Arduino (Uno) turns off.
This is the driver I am using: http://shop.moderndevice.com/products/20x4lcd-lcd117asmb