The CP Manager doesn't recognize two VMeters (http://www.vmeter.net, Revision A).
There's only one showing up in the CP Manager (probably because they use the same port name).
Studio One sees both devices, though.
When I rename the devices in the Audio/MIDI application of OS X they are both showing up.
So not a big thing for me, but as far as I know this can be a problem on some Windows systems.