Let's see what Elbox has to say.
Have you checked if pci.library is actually present in your SYS:LIBS folder?
Other than that, I hope it's a jumper issue. Mediator ZIV is I guess the trickiest one of all Mediators to configure, as there's also jumpers on ZIV busboard that need to be configured so that the two expansions could work in sync with each other.