Groove Agent 5: trouble locking outputs

Hi,
I’m setting up some instances of groove agent 5 and am having trouble setting the multiple outputs to lock between auditioning different patches.
Seems to work OK with the electronic kits, but in Acoustic Agent, it always resets to the default (all sounds through main output)…the padlock on the bottom only gives me the option to 'lock pad colours"… any advice?
Thanks