You know, I'm having trouble with my LCD as well. It's a bit flaky. I have ( what appears to be ) a LCM1602C that came with the starter kit. I've wired it up correctly, done the tutorial and I'm able to send it text and display it, however, I have intermittent problems where it will fail to display a line, or show garbage, or replace one character with the wrong one, or append trash on the end of the line. I'm not sure if my problem is that my LiquidCrystal library is older or if I've got a bad part.