Is this something to do with pin 1 being the Tx pin ? If so, can I disable that Tx function and use pin 1 for the LCD, or will that kill the Serial Monitor feature of the IDE ?
Stay away from pins 0 and 1 if you are using the serial monitor. With all of the pins available on the Mega why are you having so much trouble finding a free one?
If your initial setup worked with
LiquidCrystal lcd(2, 3, 4, 5, 6, 7);
and you cannot use pin 4 then all you have to do is find one other free pin and use it in place of pin 4. You would then use
LiquidCrystal lcd(2, 3, [b]x[/b], 5, 6, 7);
where 'x' is the free pin.
Don