what pins are you using in your lcd constructor?
Most of the LCD keypad shields I've seen don't use the same Arduino pins as
the LiquidCrystal library demo sketches.
They use this pinout:
/* The pins:
* LCD RS pin to digital pin 8
* LCD Enable pin to digital pin 9
* LCD D4 pin to digital pin 4
* LCD D5 pin to digital pin 5
* LCD D6 pin to digital pin 6
* LCD D7 pin to digital pin 7
* LCD R/W pin to ground
*/
// initialize the library with the numbers of the interface pins
// lcd(RS, E, d4, d5, d6, d7)
LiquidCrystal lcd( 8, 9, 4, 5, 6, 7);
Instead of the default pinout in IDE supplied demos of:
/*
* LCD RS pin to digital pin 12
* LCD Enable pin to digital pin 11
* LCD D4 pin to digital pin 5
* LCD D5 pin to digital pin 4
* LCD D6 pin to digital pin 3
* LCD D7 pin to digital pin 2
* LCD R/W pin to ground
*/
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
Change/fix the pins, and I bet the shield will work.
--- bill