Bridged Veras and 2 USB-UIRTs (1 on each Vera), but only 1 works

I’m having trouble getting a 2nd USB-UIRT to work on my bridged Vera 2. I have a Vera3 with a working one, and now plugging a 2nd unit into my bridged Vera2 doesn’t seem to work.

I have a feeling it’s because the deviceids, serviceids, etc in the D_USB_UIRT.xml files are he same for both, but I’m not sure what needs to be changed.

As you can see in my screenshots, there’s only an option to send pronto codes on one of my units:

Could anyone help, please?

I’ve switched over the physical USB-UIRTs and they both work in the Vera 3, just not in the bridged Vera 2. I’ve tried both USB ports in the Vera 2 too, and they work fine with other devices.

Why does bridging screw it up? I have an x10 serial to usb device plugged in as well, and it doesn’t mind being bridged.