2 Pics, 1 Serial LCD

[Armadus]

I have a circuit that uses 2 Microchip PIC18F242 chips, programmed with PicBasic Pro. I would like to use a single serial LCD controlled by each of the chips. (See attached diagram).

The program from the first PIC sends: Serout LCD, ON9600, [poscmd, 64, "Battery Voltage"]
After a 1 second pause the program from the second PIC sends: Serout LCD, ON9600, [poscmd, 104, "OK"]

The "Battery Voltage" message appears as expected, but when the second program is sent the screen goes blank.

Note: I tried using N9600, and the first message appeared as expected, but the second message displayed, but not as expected.

The LCD displays the message from either individual chip correctly, when the other chip is not in the circuit.

Any suggestions?