tagan, How long are you waiting after poweron for the 16f877 before you powerup the 12f675? I notice that you only send the data once and end the program execution. Maybe you are not waiting long enough for the LCD display to initialize before sending the data to it. I would place a delay before the data is sent to the LCD display and make sure the 16F877 is ready to receive the data before you send it.

Dave Purola,
N8NTA