Layla24 and Mona PCI cards interchangeable. How?

[Spacey]

A few years ago my Mona PCI card got damaged, so I contacted Echo support. They sent me a Layla24 PCI card (or at least it said Layla24 on the chip) and it worked. Now I'm re-installing my hardware on a different computer and the Layla card won't work with my Mona.

In Windows XP (32-bit) first it shows up as an unknown media controller. When I tell the Wizard to search for the best driver, it comes up empty. So next I tell it I'll specify the driver, and I point to Echo24Family.inf, and when the choices come up I select Mona.

I'm pretty sure that's how I did it before, but now it doesn't work at all. The Mona remains dead. Did I forget something? I'm about to contact Echo support but figured I'd ask here first.