Disable Chime on Disarm in OmniPro II

I recently upgraded my 2 layer chip to 4.0 in my OmniPro II panel  
 
Prior to the upgrade, my Alarm would chime on Arm, but it was set to not chime on Disarm.
 
All my programming seems to have stayed the same during the upgrade, except for the Disarming Chime.
 
I've searched everywhere, and can't find where the option is to disable the chime on Disarming?
 
Anyone suggestions?
 
Thanks
Bernie