Micrologix 1200 channel 0 resets itself on reboot

I've set the channel 0 communications port (this is a two port unit) to 9600 baud to accomodate a display panel connected to that port. On ever power off/on event, the channel 0 port resets itself to 19200 baud, which then requires me to reset the port yet again to 9600.

Can anyone help me understand how to get the 9600 baud setting to stick, even through a power off/on cycle? To my knowledge, nobody (even the gremlins we have) is pressing the button to reset the port.

Is there a memory module installed? If so have you stored the comm changes to it? There is also a write protection check box to prevent changes from a memory module. (see channel configuration)